From 8f31fbd10e003aa4e012852feb08badb99a7f6d5 Mon Sep 17 00:00:00 2001
From: Krishan Koenig <krishan.koenig@googlemail.com>
Date: Tue, 10 Dec 2024 13:50:24 +0100
Subject: [PATCH] add sales invoices endpoint

---
 docs/endpoint-collections.md                  |  66 +++++++
 .../SalesInvoiceEndpointCollection.php        | 109 ++++++++++++
 .../CreateSalesInvoicePayloadFactory.php      |  40 +++++
 .../InvoiceLineCollectionFactory.php          |  16 ++
 src/Factories/InvoiceLineFactory.php          |  20 +++
 src/Factories/RecipientFactory.php            |  30 ++++
 .../UpdateSalesInvoicePayloadFactory.php      |  36 ++++
 .../Payload/CreateSalesInvoicePayload.php     |  93 ++++++++++
 src/Http/Payload/Discount.php                 |  31 ++++
 src/Http/Payload/EmailDetails.php             |  30 ++++
 src/Http/Payload/InvoiceLine.php              |  41 +++++
 src/Http/Payload/PaymentDetails.php           |  31 ++++
 src/Http/Payload/Recipient.php                |  98 ++++++++++
 .../Payload/UpdateSalesInvoicePayload.php     |  69 ++++++++
 .../Requests/CreateSalesInvoiceRequest.php    |  34 ++++
 .../Requests/DeleteSalesInvoiceRequest.php    |  23 +++
 .../GetPaginatedSalesInvoicesRequest.php      |  20 +++
 src/Http/Requests/GetSalesInvoiceRequest.php  |  31 ++++
 .../Requests/UpdateSalesInvoiceRequest.php    |  36 ++++
 src/MollieApiClient.php                       |   6 +-
 src/Resources/SalesInvoice.php                | 167 ++++++++++++++++++
 src/Resources/SalesInvoiceCollection.php      |  16 ++
 src/Traits/HasEndpoints.php                   |   2 +
 src/Types/PaymentTerm.php                     |  14 ++
 src/Types/RecipientType.php                   |   9 +
 src/Types/SalesInvoiceStatus.php              |  21 +++
 src/Types/VatMode.php                         |   9 +
 src/Types/VatScheme.php                       |   9 +
 .../SalesInvoiceEndpointCollectionTest.php    | 136 ++++++++++++++
 .../Responses/sales-invoice-list.json         |  83 +++++++++
 tests/Fixtures/Responses/sales-invoice.json   |  81 +++++++++
 .../CreateSalesInvoiceRequestTest.php         |  98 ++++++++++
 .../DeleteSalesInvoiceRequestTest.php         |  34 ++++
 .../GetPaginatedSalesInvoicesRequestTest.php  |  69 ++++++++
 .../Requests/GetSalesInvoiceRequestTest.php   |  26 +++
 .../UpdateSalesInvoiceRequestTest.php         |  44 +++++
 36 files changed, 1676 insertions(+), 2 deletions(-)
 create mode 100644 src/EndpointCollection/SalesInvoiceEndpointCollection.php
 create mode 100644 src/Factories/CreateSalesInvoicePayloadFactory.php
 create mode 100644 src/Factories/InvoiceLineCollectionFactory.php
 create mode 100644 src/Factories/InvoiceLineFactory.php
 create mode 100644 src/Factories/RecipientFactory.php
 create mode 100644 src/Factories/UpdateSalesInvoicePayloadFactory.php
 create mode 100644 src/Http/Payload/CreateSalesInvoicePayload.php
 create mode 100644 src/Http/Payload/Discount.php
 create mode 100644 src/Http/Payload/EmailDetails.php
 create mode 100644 src/Http/Payload/InvoiceLine.php
 create mode 100644 src/Http/Payload/PaymentDetails.php
 create mode 100644 src/Http/Payload/Recipient.php
 create mode 100644 src/Http/Payload/UpdateSalesInvoicePayload.php
 create mode 100644 src/Http/Requests/CreateSalesInvoiceRequest.php
 create mode 100644 src/Http/Requests/DeleteSalesInvoiceRequest.php
 create mode 100644 src/Http/Requests/GetPaginatedSalesInvoicesRequest.php
 create mode 100644 src/Http/Requests/GetSalesInvoiceRequest.php
 create mode 100644 src/Http/Requests/UpdateSalesInvoiceRequest.php
 create mode 100644 src/Resources/SalesInvoice.php
 create mode 100644 src/Resources/SalesInvoiceCollection.php
 create mode 100644 src/Types/PaymentTerm.php
 create mode 100644 src/Types/RecipientType.php
 create mode 100644 src/Types/SalesInvoiceStatus.php
 create mode 100644 src/Types/VatMode.php
 create mode 100644 src/Types/VatScheme.php
 create mode 100644 tests/EndpointCollection/SalesInvoiceEndpointCollectionTest.php
 create mode 100644 tests/Fixtures/Responses/sales-invoice-list.json
 create mode 100644 tests/Fixtures/Responses/sales-invoice.json
 create mode 100644 tests/Http/Requests/CreateSalesInvoiceRequestTest.php
 create mode 100644 tests/Http/Requests/DeleteSalesInvoiceRequestTest.php
 create mode 100644 tests/Http/Requests/GetPaginatedSalesInvoicesRequestTest.php
 create mode 100644 tests/Http/Requests/GetSalesInvoiceRequestTest.php
 create mode 100644 tests/Http/Requests/UpdateSalesInvoiceRequestTest.php

diff --git a/docs/endpoint-collections.md b/docs/endpoint-collections.md
index 6a0f7c2c..4dee3bf8 100644
--- a/docs/endpoint-collections.md
+++ b/docs/endpoint-collections.md
@@ -521,6 +521,72 @@ $refund = $mollie->refunds->createForPayment($paymentId, [
 $refunds = $mollie->refunds->page();
 ```
 
+## Sales Invoices
+
+[Official Documentation TBA]
+
+**Available Payloads:**
+- `CreateSalesInvoicePayload` - For creating sales invoices
+- `UpdateSalesInvoicePayload` - For updating existing sales invoices
+
+**Available Queries:**
+- `GetPaginatedSalesInvoiceQuery` - For listing sales invoices with pagination
+
+### Sales Invoice Management
+
+```php
+use Mollie\Api\Types\VatMode;
+use Mollie\Api\Types\VatScheme;
+use Mollie\Api\Types\PaymentTerm;
+use Mollie\Api\Types\RecipientType;
+use Mollie\Api\Types\RecipientType;
+use Mollie\Api\Types\SalesInvoiceStatus;
+
+// Create a sales invoice
+$salesInvoice = $mollie->salesInvoices->create([
+    'currency' => 'EUR',
+    'status' => SalesInvoiceStatus::DRAFT,
+    'vatScheme' => VatScheme::STANDARD,
+    'vatMode' => VatMode::INCLUSIVE,
+    'paymentTerm' => PaymentTerm::DAYS_30,
+    'recipientIdentifier' => 'XXXXX',
+    'recipient' => [
+        'type' => RecipientType::CONSUMER,
+        'email' => 'darth@vader.deathstar',
+        'streetAndNumber' => 'Sample Street 12b',
+        'postalCode' => '2000 AA',
+        'city' => 'Amsterdam',
+        'country' => 'NL',
+        'locale' => 'nl_NL'
+    ],
+    'lines' => [
+        [
+            'description' => 'Monthly subscription fee',
+            'quantity' => 1,
+            'vatRate' => '21',
+            'unitPrice' => [
+                'currency' => 'EUR',
+                'value' => '10,00'
+            ]
+        ]
+    ]
+]);
+
+// Get a sales invoice
+$salesInvoice = $mollie->salesInvoices->get('invoice_12345');
+
+// Update a sales invoice
+$salesInvoice = $mollie->salesInvoices->update('invoice_12345', [
+    'description' => 'Updated description'
+]);
+
+// Delete a sales invoice
+$mollie->salesInvoices->delete('invoice_12345');
+
+// List sales invoices
+$salesInvoices = $mollie->salesInvoices->page();
+```
+
 ## Sessions
 
 [Official Documentation](https://docs.mollie.com/reference/v2/sessions-api/create-session)
diff --git a/src/EndpointCollection/SalesInvoiceEndpointCollection.php b/src/EndpointCollection/SalesInvoiceEndpointCollection.php
new file mode 100644
index 00000000..c1b28f78
--- /dev/null
+++ b/src/EndpointCollection/SalesInvoiceEndpointCollection.php
@@ -0,0 +1,109 @@
+<?php
+
+namespace Mollie\Api\EndpointCollection;
+
+use Mollie\Api\Exceptions\ApiException;
+use Mollie\Api\Factories\CreateSalesInvoicePayloadFactory;
+use Mollie\Api\Factories\PaginatedQueryFactory;
+use Mollie\Api\Factories\UpdateSalesInvoicePayloadFactory;
+use Mollie\Api\Http\Payload\CreateSalesInvoicePayload;
+use Mollie\Api\Http\Payload\UpdateSalesInvoicePayload;
+use Mollie\Api\Http\Requests\CreateSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\DeleteSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\GetPaginatedSalesInvoicesRequest;
+use Mollie\Api\Http\Requests\GetSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\UpdateSalesInvoiceRequest;
+use Mollie\Api\Resources\LazyCollection;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Resources\SalesInvoiceCollection;
+
+class SalesInvoiceEndpointCollection extends EndpointCollection
+{
+    /**
+     * Retrieve a SalesInvoice from Mollie.
+     *
+     * @throws ApiException
+     */
+    public function get(string $id): SalesInvoice
+    {
+        return $this->send(new GetSalesInvoiceRequest($id));
+    }
+
+    /**
+     * Creates a SalesInvoice in Mollie.
+     *
+     * @param array|CreateSalesInvoicePayload $payload
+     *
+     * @throws ApiException
+     */
+    public function create($payload = []): SalesInvoice
+    {
+        if (! $payload instanceof CreateSalesInvoicePayload) {
+            $payload = CreateSalesInvoicePayloadFactory::new($payload)->create();
+        }
+
+        return $this->send(new CreateSalesInvoiceRequest($payload));
+    }
+
+    /**
+     * Update a specific SalesInvoice resource.
+     *
+     * @throws ApiException
+     */
+    public function update(string $id, $payload = []): ?SalesInvoice
+    {
+        if (! $payload instanceof UpdateSalesInvoicePayload) {
+            $payload = UpdateSalesInvoicePayloadFactory::new($payload)->create();
+        }
+
+        return $this->send(new UpdateSalesInvoiceRequest($id, $payload));
+    }
+
+    /**
+     * Delete a SalesInvoice from Mollie.
+     *
+     * @throws ApiException
+     */
+    public function delete(string $id): void
+    {
+        $this->send(new DeleteSalesInvoiceRequest($id));
+    }
+
+    /**
+     * Retrieves a collection of SalesInvoices from Mollie.
+     *
+     * @throws ApiException
+     */
+    public function page(?string $from = null, ?int $limit = null): SalesInvoiceCollection
+    {
+        $query = PaginatedQueryFactory::new([
+            'from' => $from,
+            'limit' => $limit,
+        ])->create();
+
+        return $this->send(new GetPaginatedSalesInvoicesRequest($query));
+    }
+
+    /**
+     * Create an iterator for iterating over sales invoices retrieved from Mollie.
+     *
+     * @param  string|null  $from  The first resource ID you want to include in your list.
+     * @param  bool  $iterateBackwards  Set to true for reverse order iteration (default is false).
+     */
+    public function iterator(
+        ?string $from = null,
+        ?int $limit = null,
+        bool $iterateBackwards = false
+    ): LazyCollection {
+        $query = PaginatedQueryFactory::new([
+            'from' => $from,
+            'limit' => $limit,
+        ])->create();
+
+        return $this->send(
+            (new GetPaginatedSalesInvoicesRequest($query))
+                ->useIterator()
+                ->setIterationDirection($iterateBackwards)
+        );
+    }
+}
diff --git a/src/Factories/CreateSalesInvoicePayloadFactory.php b/src/Factories/CreateSalesInvoicePayloadFactory.php
new file mode 100644
index 00000000..de6200a6
--- /dev/null
+++ b/src/Factories/CreateSalesInvoicePayloadFactory.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Mollie\Api\Factories;
+
+use Mollie\Api\Http\Payload\CreateSalesInvoicePayload;
+use Mollie\Api\Http\Payload\PaymentDetails;
+use Mollie\Api\Http\Payload\EmailDetails;
+use Mollie\Api\Http\Payload\Discount;
+
+class CreateSalesInvoicePayloadFactory extends Factory
+{
+    /**
+     * Create a new CreateSalesInvoicePayload instance.
+     *
+     * @return CreateSalesInvoicePayload
+     */
+    public function create(): CreateSalesInvoicePayload
+    {
+        return new CreateSalesInvoicePayload(
+            $this->get('currency'),
+            $this->get('status'),
+            $this->get('vatScheme'),
+            $this->get('vatMode'),
+            $this->get('paymentTerm'),
+            $this->get('recipientIdentifier'),
+            RecipientFactory::new($this->get('recipient'))->create(),
+            $this
+                ->mapIfNotNull(
+                    'lines',
+                    fn(array $items) => InvoiceLineCollectionFactory::new($items)->create()
+                ),
+            $this->get('profileId'),
+            $this->get('memo'),
+            $this->mapIfNotNull('paymentDetails', fn(array $data) => PaymentDetails::fromArray($data)),
+            $this->mapIfNotNull('emailDetails', fn(array $data) => EmailDetails::fromArray($data)),
+            $this->get('webhookUrl'),
+            $this->mapIfNotNull('discount', fn(array $data) => Discount::fromArray($data))
+        );
+    }
+}
diff --git a/src/Factories/InvoiceLineCollectionFactory.php b/src/Factories/InvoiceLineCollectionFactory.php
new file mode 100644
index 00000000..d90f10f3
--- /dev/null
+++ b/src/Factories/InvoiceLineCollectionFactory.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Mollie\Api\Factories;
+
+use Mollie\Api\Http\Payload\DataCollection;
+
+class InvoiceLineCollectionFactory extends Factory
+{
+    public function create(): DataCollection
+    {
+        return new DataCollection(array_map(
+            fn(array $item) => InvoiceLineFactory::new($item)->create(),
+            $this->data
+        ));
+    }
+}
diff --git a/src/Factories/InvoiceLineFactory.php b/src/Factories/InvoiceLineFactory.php
new file mode 100644
index 00000000..bd929792
--- /dev/null
+++ b/src/Factories/InvoiceLineFactory.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Mollie\Api\Factories;
+
+use Mollie\Api\Http\Payload\Discount;
+use Mollie\Api\Http\Payload\InvoiceLine;
+
+class InvoiceLineFactory extends Factory
+{
+    public function create(): InvoiceLine
+    {
+        return new InvoiceLine(
+            $this->get('description'),
+            $this->get('quantity'),
+            $this->get('vatRate'),
+            MoneyFactory::new($this->get('unitPrice'))->create(),
+            $this->mapIfNotNull('discount', fn(array $data) => Discount::fromArray($data))
+        );
+    }
+}
diff --git a/src/Factories/RecipientFactory.php b/src/Factories/RecipientFactory.php
new file mode 100644
index 00000000..31d64a87
--- /dev/null
+++ b/src/Factories/RecipientFactory.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Mollie\Api\Factories;
+
+use Mollie\Api\Http\Payload\Recipient;
+
+class RecipientFactory extends Factory
+{
+    public function create(): Recipient
+    {
+        return new Recipient(
+            $this->get('type'),
+            $this->get('email'),
+            $this->get('streetAndNumber'),
+            $this->get('postalCode'),
+            $this->get('city'),
+            $this->get('country'),
+            $this->get('locale'),
+            $this->get('title'),
+            $this->get('givenName'),
+            $this->get('familyName'),
+            $this->get('organizationName'),
+            $this->get('organizationNumber'),
+            $this->get('vatNumber'),
+            $this->get('phone'),
+            $this->get('streetAdditional'),
+            $this->get('region'),
+        );
+    }
+}
diff --git a/src/Factories/UpdateSalesInvoicePayloadFactory.php b/src/Factories/UpdateSalesInvoicePayloadFactory.php
new file mode 100644
index 00000000..005780d2
--- /dev/null
+++ b/src/Factories/UpdateSalesInvoicePayloadFactory.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Mollie\Api\Factories;
+
+use Mollie\Api\Http\Payload\UpdateSalesInvoicePayload;
+use Mollie\Api\Http\Payload\PaymentDetails;
+use Mollie\Api\Http\Payload\EmailDetails;
+use Mollie\Api\Http\Payload\Discount;
+
+class UpdateSalesInvoicePayloadFactory extends Factory
+{
+    /**
+     * Create a new UpdateSalesInvoicePayload instance.
+     *
+     * @return UpdateSalesInvoicePayload
+     */
+    public function create(): UpdateSalesInvoicePayload
+    {
+        return new UpdateSalesInvoicePayload(
+            $this->get('status'),
+            $this->get('recipientIdentifier'),
+            $this->get('paymentTerm'),
+            $this->get('memo'),
+            $this->mapIfNotNull('paymentDetails', fn(array $data) => PaymentDetails::fromArray($data)),
+            $this->mapIfNotNull('emailDetails', fn(array $data) => EmailDetails::fromArray($data)),
+            $this->mapIfNotNull('recipient', fn(array $data) => RecipientFactory::new($data)->create()),
+            $this
+                ->mapIfNotNull(
+                    'lines',
+                    fn(array $items) => InvoiceLineCollectionFactory::new($items)->create()
+                ),
+            $this->get('webhookUrl'),
+            $this->mapIfNotNull('discount', fn(array $data) => Discount::fromArray($data))
+        );
+    }
+}
diff --git a/src/Http/Payload/CreateSalesInvoicePayload.php b/src/Http/Payload/CreateSalesInvoicePayload.php
new file mode 100644
index 00000000..4ff3b308
--- /dev/null
+++ b/src/Http/Payload/CreateSalesInvoicePayload.php
@@ -0,0 +1,93 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+use Mollie\Api\Types\PaymentTerm;
+use Mollie\Api\Types\VatMode;
+use Mollie\Api\Types\VatScheme;
+
+class CreateSalesInvoicePayload extends DataBag
+{
+    public ?string $profileId;
+
+    public string $currency;
+
+    public string $status;
+
+    public string $vatScheme = VatScheme::STANDARD;
+
+    public string $vatMode = VatMode::EXCLUSIVE;
+
+    public ?string $memo;
+
+    public string $paymentTerm = PaymentTerm::DAYS_30;
+
+    public ?PaymentDetails $paymentDetails;
+
+    public ?EmailDetails $emailDetails;
+
+    public string $recipientIdentifier;
+
+    public Recipient $recipient;
+
+    /**
+     * @var DataCollection<InvoiceLine>
+     */
+    public DataCollection $lines;
+
+    public ?string $webhookUrl;
+
+    public ?Discount $discount;
+
+    public function __construct(
+        string $currency,
+        string $status,
+        string $vatScheme,
+        string $vatMode,
+        string $paymentTerm,
+        string $recipientIdentifier,
+        Recipient $recipient,
+        DataCollection $lines,
+        ?string $profileId = null,
+        ?string $memo = null,
+        ?PaymentDetails $paymentDetails = null,
+        ?EmailDetails $emailDetails = null,
+        ?string $webhookUrl = null,
+        ?Discount $discount = null,
+    ) {
+        $this->profileId = $profileId;
+        $this->currency = $currency;
+        $this->status = $status;
+        $this->vatScheme = $vatScheme;
+        $this->vatMode = $vatMode;
+        $this->memo = $memo;
+        $this->paymentTerm = $paymentTerm;
+        $this->paymentDetails = $paymentDetails;
+        $this->emailDetails = $emailDetails;
+        $this->recipientIdentifier = $recipientIdentifier;
+        $this->recipient = $recipient;
+        $this->lines = $lines;
+        $this->webhookUrl = $webhookUrl;
+        $this->discount = $discount;
+    }
+
+    public function data(): array
+    {
+        return [
+            'profileId' => $this->profileId,
+            'currency' => $this->currency,
+            'status' => $this->status,
+            'vatScheme' => $this->vatScheme,
+            'vatMode' => $this->vatMode,
+            'memo' => $this->memo,
+            'paymentTerm' => $this->paymentTerm,
+            'paymentDetails' => $this->paymentDetails,
+            'emailDetails' => $this->emailDetails,
+            'recipientIdentifier' => $this->recipientIdentifier,
+            'recipient' => $this->recipient,
+            'lines' => $this->lines,
+            'webhookUrl' => $this->webhookUrl,
+            'discount' => $this->discount,
+        ];
+    }
+}
diff --git a/src/Http/Payload/Discount.php b/src/Http/Payload/Discount.php
new file mode 100644
index 00000000..3207fe1e
--- /dev/null
+++ b/src/Http/Payload/Discount.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+use Mollie\Api\Contracts\DataProvider;
+use Mollie\Api\Traits\ComposableFromArray;
+
+class Discount implements DataProvider
+{
+    use ComposableFromArray;
+
+    public string $type;
+
+    public string $value;
+
+    public function __construct(
+        string $type,
+        string $value,
+    ) {
+        $this->type = $type;
+        $this->value = $value;
+    }
+
+    public function data()
+    {
+        return [
+            'type' => $this->type,
+            'value' => $this->value,
+        ];
+    }
+}
diff --git a/src/Http/Payload/EmailDetails.php b/src/Http/Payload/EmailDetails.php
new file mode 100644
index 00000000..be78009d
--- /dev/null
+++ b/src/Http/Payload/EmailDetails.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+use Mollie\Api\Contracts\DataProvider;
+use Mollie\Api\Traits\ComposableFromArray;
+
+class EmailDetails implements DataProvider
+{
+    use ComposableFromArray;
+    public string $subject;
+
+    public string $body;
+
+    public function __construct(
+        string $subject,
+        string $body,
+    ) {
+        $this->subject = $subject;
+        $this->body = $body;
+    }
+
+    public function data()
+    {
+        return [
+            'subject' => $this->subject,
+            'body' => $this->body,
+        ];
+    }
+}
diff --git a/src/Http/Payload/InvoiceLine.php b/src/Http/Payload/InvoiceLine.php
new file mode 100644
index 00000000..ced72bd6
--- /dev/null
+++ b/src/Http/Payload/InvoiceLine.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+class InvoiceLine extends DataBag
+{
+    public string $description;
+
+    public int $quantity;
+
+    public string $vatRate;
+
+    public Money $unitPrice;
+
+    public ?Discount $discount;
+
+    public function __construct(
+        string $description,
+        int $quantity,
+        string $vatRate,
+        Money $unitPrice,
+        ?Discount $discount = null,
+    ) {
+        $this->description = $description;
+        $this->quantity = $quantity;
+        $this->vatRate = $vatRate;
+        $this->unitPrice = $unitPrice;
+        $this->discount = $discount;
+    }
+
+    public function data()
+    {
+        return [
+            'description' => $this->description,
+            'quantity' => $this->quantity,
+            'vatRate' => $this->vatRate,
+            'unitPrice' => $this->unitPrice,
+            'discount' => $this->discount,
+        ];
+    }
+}
diff --git a/src/Http/Payload/PaymentDetails.php b/src/Http/Payload/PaymentDetails.php
new file mode 100644
index 00000000..ad224023
--- /dev/null
+++ b/src/Http/Payload/PaymentDetails.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+use Mollie\Api\Contracts\DataProvider;
+use Mollie\Api\Traits\ComposableFromArray;
+
+class PaymentDetails implements DataProvider
+{
+    use ComposableFromArray;
+
+    public string $source;
+
+    public ?string $sourceDescription;
+
+    public function __construct(
+        string $source,
+        ?string $sourceDescription = null,
+    ) {
+        $this->source = $source;
+        $this->sourceDescription = $sourceDescription;
+    }
+
+    public function data()
+    {
+        return [
+            'source' => $this->source,
+            'sourceDescription' => $this->sourceDescription,
+        ];
+    }
+}
diff --git a/src/Http/Payload/Recipient.php b/src/Http/Payload/Recipient.php
new file mode 100644
index 00000000..bff22594
--- /dev/null
+++ b/src/Http/Payload/Recipient.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+use Mollie\Api\Contracts\DataProvider;
+
+class Recipient implements DataProvider
+{
+    public string $type;
+
+    public ?string $title;
+
+    public ?string $givenName;
+
+    public ?string $familyName;
+
+    public ?string $organizationName;
+
+    public ?string $organizationNumber;
+
+    public ?string $vatNumber;
+
+    public string $email;
+
+    public ?string $phone;
+
+    public string $streetAndNumber;
+
+    public ?string $streetAdditional;
+
+    public string $postalCode;
+
+    public string $city;
+
+    public ?string $region;
+
+    public string $country;
+
+    public string $locale;
+
+    public function __construct(
+        string $type,
+        string $email,
+        string $streetAndNumber,
+        string $postalCode,
+        string $city,
+        string $country,
+        string $locale,
+        ?string $title = null,
+        ?string $givenName = null,
+        ?string $familyName = null,
+        ?string $organizationName = null,
+        ?string $organizationNumber = null,
+        ?string $vatNumber = null,
+        ?string $phone = null,
+        ?string $streetAdditional = null,
+        ?string $region = null,
+    ) {
+        $this->type = $type;
+        $this->title = $title;
+        $this->givenName = $givenName;
+        $this->familyName = $familyName;
+        $this->organizationName = $organizationName;
+        $this->organizationNumber = $organizationNumber;
+        $this->vatNumber = $vatNumber;
+        $this->email = $email;
+        $this->phone = $phone;
+        $this->streetAndNumber = $streetAndNumber;
+        $this->streetAdditional = $streetAdditional;
+        $this->postalCode = $postalCode;
+        $this->city = $city;
+        $this->region = $region;
+        $this->country = $country;
+        $this->locale = $locale;
+    }
+
+    public function data()
+    {
+        return [
+            'type' => $this->type,
+            'title' => $this->title,
+            'givenName' => $this->givenName,
+            'familyName' => $this->familyName,
+            'organizationName' => $this->organizationName,
+            'organizationNumber' => $this->organizationNumber,
+            'vatNumber' => $this->vatNumber,
+            'email' => $this->email,
+            'phone' => $this->phone,
+            'streetAndNumber' => $this->streetAndNumber,
+            'streetAdditional' => $this->streetAdditional,
+            'postalCode' => $this->postalCode,
+            'city' => $this->city,
+            'region' => $this->region,
+            'country' => $this->country,
+            'locale' => $this->locale,
+        ];
+    }
+}
diff --git a/src/Http/Payload/UpdateSalesInvoicePayload.php b/src/Http/Payload/UpdateSalesInvoicePayload.php
new file mode 100644
index 00000000..634a25f0
--- /dev/null
+++ b/src/Http/Payload/UpdateSalesInvoicePayload.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Mollie\Api\Http\Payload;
+
+class UpdateSalesInvoicePayload extends DataBag
+{
+    public string $status;
+
+    public ?string $memo;
+
+    public ?string $paymentTerm;
+
+    public ?PaymentDetails $paymentDetails;
+
+    public ?EmailDetails $emailDetails;
+
+    public string $recipientIdentifier;
+
+    public ?Recipient $recipient;
+
+    /**
+     * @var DataCollection<InvoiceLine>
+     */
+    public ?DataCollection $lines;
+
+    public ?string $webhookUrl;
+
+    public ?Discount $discount;
+
+    public function __construct(
+        string $status,
+        string $recipientIdentifier,
+        ?string $paymentTerm = null,
+        ?string $memo = null,
+        ?PaymentDetails $paymentDetails = null,
+        ?EmailDetails $emailDetails = null,
+        ?Recipient $recipient = null,
+        ?DataCollection $lines = null,
+        ?string $webhookUrl = null,
+        ?Discount $discount = null,
+    ) {
+        $this->status = $status;
+        $this->paymentTerm = $paymentTerm;
+        $this->recipientIdentifier = $recipientIdentifier;
+        $this->memo = $memo;
+        $this->paymentDetails = $paymentDetails;
+        $this->emailDetails = $emailDetails;
+        $this->recipient = $recipient;
+        $this->lines = $lines;
+        $this->webhookUrl = $webhookUrl;
+        $this->discount = $discount;
+    }
+
+    public function data(): array
+    {
+        return [
+            'status' => $this->status,
+            'memo' => $this->memo,
+            'paymentTerm' => $this->paymentTerm,
+            'paymentDetails' => $this->paymentDetails,
+            'emailDetails' => $this->emailDetails,
+            'recipientIdentifier' => $this->recipientIdentifier,
+            'recipient' => $this->recipient,
+            'lines' => $this->lines,
+            'webhookUrl' => $this->webhookUrl,
+            'discount' => $this->discount,
+        ];
+    }
+}
diff --git a/src/Http/Requests/CreateSalesInvoiceRequest.php b/src/Http/Requests/CreateSalesInvoiceRequest.php
new file mode 100644
index 00000000..18168770
--- /dev/null
+++ b/src/Http/Requests/CreateSalesInvoiceRequest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Mollie\Api\Http\Requests;
+
+use Mollie\Api\Contracts\HasPayload;
+use Mollie\Api\Http\Payload\CreateSalesInvoicePayload;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Traits\HasJsonPayload;
+use Mollie\Api\Types\Method;
+
+class CreateSalesInvoiceRequest extends ResourceHydratableRequest implements HasPayload
+{
+    use HasJsonPayload;
+
+    protected static string $method = Method::POST;
+    public static string $targetResourceClass = SalesInvoice::class;
+
+    private CreateSalesInvoicePayload $payload;
+
+    public function __construct(CreateSalesInvoicePayload $payload)
+    {
+        $this->payload = $payload;
+    }
+
+    public function resolveResourcePath(): string
+    {
+        return 'sales-invoices';
+    }
+
+    public function defaultPayload(): array
+    {
+        return $this->payload->toArray();
+    }
+}
diff --git a/src/Http/Requests/DeleteSalesInvoiceRequest.php b/src/Http/Requests/DeleteSalesInvoiceRequest.php
new file mode 100644
index 00000000..c1d56cf2
--- /dev/null
+++ b/src/Http/Requests/DeleteSalesInvoiceRequest.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Mollie\Api\Http\Requests;
+
+use Mollie\Api\Http\Request;
+use Mollie\Api\Types\Method;
+
+class DeleteSalesInvoiceRequest extends Request
+{
+    protected static string $method = Method::DELETE;
+
+    private string $id;
+
+    public function __construct(string $id)
+    {
+        $this->id = $id;
+    }
+
+    public function resolveResourcePath(): string
+    {
+        return "sales-invoices/{$this->id}";
+    }
+}
diff --git a/src/Http/Requests/GetPaginatedSalesInvoicesRequest.php b/src/Http/Requests/GetPaginatedSalesInvoicesRequest.php
new file mode 100644
index 00000000..d88095a9
--- /dev/null
+++ b/src/Http/Requests/GetPaginatedSalesInvoicesRequest.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Mollie\Api\Http\Requests;
+
+use Mollie\Api\Contracts\IsIteratable;
+use Mollie\Api\Contracts\SupportsTestmodeInQuery;
+use Mollie\Api\Resources\SalesInvoiceCollection;
+use Mollie\Api\Traits\IsIteratableRequest;
+
+class GetPaginatedSalesInvoicesRequest extends PaginatedRequest implements IsIteratable, SupportsTestmodeInQuery
+{
+    use IsIteratableRequest;
+
+    public static string $targetResourceClass = SalesInvoiceCollection::class;
+
+    public function resolveResourcePath(): string
+    {
+        return 'sales-invoices';
+    }
+}
diff --git a/src/Http/Requests/GetSalesInvoiceRequest.php b/src/Http/Requests/GetSalesInvoiceRequest.php
new file mode 100644
index 00000000..282a4237
--- /dev/null
+++ b/src/Http/Requests/GetSalesInvoiceRequest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Mollie\Api\Http\Requests;
+
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Types\Method;
+
+class GetSalesInvoiceRequest extends ResourceHydratableRequest
+{
+    /**
+     * Define the HTTP method.
+     */
+    protected static string $method = Method::GET;
+
+    /**
+     * The resource class the request should be casted to.
+     */
+    public static string $targetResourceClass = SalesInvoice::class;
+
+    private string $id;
+
+    public function __construct(string $id)
+    {
+        $this->id = $id;
+    }
+
+    public function resolveResourcePath(): string
+    {
+        return "sales-invoices/{$this->id}";
+    }
+}
diff --git a/src/Http/Requests/UpdateSalesInvoiceRequest.php b/src/Http/Requests/UpdateSalesInvoiceRequest.php
new file mode 100644
index 00000000..1584378d
--- /dev/null
+++ b/src/Http/Requests/UpdateSalesInvoiceRequest.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Mollie\Api\Http\Requests;
+
+use Mollie\Api\Contracts\HasPayload;
+use Mollie\Api\Http\Payload\UpdateSalesInvoicePayload;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Traits\HasJsonPayload;
+use Mollie\Api\Types\Method;
+
+class UpdateSalesInvoiceRequest extends ResourceHydratableRequest implements HasPayload
+{
+    use HasJsonPayload;
+
+    protected static string $method = Method::PATCH;
+    public static string $targetResourceClass = SalesInvoice::class;
+
+    private string $id;
+    private UpdateSalesInvoicePayload $payload;
+
+    public function __construct(string $id, UpdateSalesInvoicePayload $payload)
+    {
+        $this->id = $id;
+        $this->payload = $payload;
+    }
+
+    public function resolveResourcePath(): string
+    {
+        return "sales-invoices/{$this->id}";
+    }
+
+    public function defaultPayload(): array
+    {
+        return $this->payload->toArray();
+    }
+}
diff --git a/src/MollieApiClient.php b/src/MollieApiClient.php
index 02747e76..77935bc6 100644
--- a/src/MollieApiClient.php
+++ b/src/MollieApiClient.php
@@ -42,6 +42,7 @@
 use Mollie\Api\EndpointCollection\SubscriptionPaymentEndpointCollection;
 use Mollie\Api\EndpointCollection\TerminalEndpointCollection;
 use Mollie\Api\EndpointCollection\WalletEndpointCollection;
+use Mollie\Api\EndpointCollection\SalesInvoiceEndpointCollection;
 use Mollie\Api\Helpers\Url;
 use Mollie\Api\Http\Adapter\MollieHttpAdapterPicker;
 use Mollie\Api\Idempotency\DefaultIdempotencyKeyGenerator;
@@ -84,15 +85,16 @@
  * @property ProfileEndpointCollection $profiles
  * @property ProfileMethodEndpointCollection $profileMethods
  * @property RefundEndpointCollection $refunds
- * @property SettlementEndpointCollection $settlements
+ * @property SalesInvoiceEndpointCollection $salesInvoices
+ * @property SessionEndpointCollection $sessions
  * @property SettlementCaptureEndpointCollection $settlementCaptures
  * @property SettlementChargebackEndpointCollection $settlementChargebacks
+ * @property SettlementEndpointCollection $settlements
  * @property SettlementPaymentEndpointCollection $settlementPayments
  * @property SettlementRefundEndpointCollection $settlementRefunds
  * @property SubscriptionEndpointCollection $subscriptions
  * @property SubscriptionPaymentEndpointCollection $subscriptionPayments
  * @property TerminalEndpointCollection $terminals
- * @property SessionEndpointCollection $sessions
  * @property WalletEndpointCollection $wallets
  * @property HttpAdapterContract $httpClient
  */
diff --git a/src/Resources/SalesInvoice.php b/src/Resources/SalesInvoice.php
new file mode 100644
index 00000000..432d0cde
--- /dev/null
+++ b/src/Resources/SalesInvoice.php
@@ -0,0 +1,167 @@
+<?php
+
+namespace Mollie\Api\Resources;
+
+use Mollie\Api\Types\SalesInvoiceStatus;
+
+class SalesInvoice extends BaseResource
+{
+    /**
+     * @var string
+     */
+    public $resource;
+
+    /**
+     * @var string
+     */
+    public $id;
+
+    /**
+     * @var string|null
+     */
+    public $profileId;
+
+    /**
+     * @var string|null
+     */
+    public $invoiceNumber;
+
+    /**
+     * @var string
+     */
+    public $currency;
+
+    /**
+     * @var string
+     */
+    public $status;
+
+    /**
+     * @var string
+     */
+    public $vatScheme;
+
+    /**
+     * @var string
+     */
+    public $vatMode;
+
+    /**
+     * @var string|null
+     */
+    public $memo;
+
+    /**
+     * @var string
+     */
+    public $paymentTerm;
+
+    /**
+     * @var object
+     */
+    public $paymentDetails;
+    /**
+     * @var object
+     */
+    public $emailDetails;
+
+    /**
+     * @var string
+     */
+    public $recipientIdentifier;
+
+    /**
+     * @var object
+     */
+    public $recipient;
+
+    /**
+     * @var array
+     */
+    public $lines;
+
+    /**
+     * @var string
+     */
+    public $webhookUrl;
+
+    /**
+     * @var object|null
+     */
+    public $discount;
+
+    /**
+     * @var object
+     */
+    public $amountDue;
+
+    /**
+     * @var object
+     */
+    public $subtotalAmount;
+
+    /**
+     * @var object
+     */
+    public $totalAmount;
+
+    /**
+     * @var object
+     */
+    public $totalVatAmount;
+
+    /**
+     * @var object
+     */
+    public $discountedSubtotalAmount;
+
+    /**
+     * @var string
+     */
+    public $createdAt;
+
+    /**
+     * @var string|null
+     */
+    public $issuedAt;
+
+    /**
+     * @var string|null
+     */
+    public $dueAt;
+
+    /**
+     * @var object
+     */
+    public $_links;
+
+    /**
+     * Returns whether the sales invoice is in draft status.
+     *
+     * @return bool
+     */
+    public function isDraft()
+    {
+        return $this->status === SalesInvoiceStatus::DRAFT;
+    }
+
+    /**
+     * Returns whether the sales invoice is issued.
+     *
+     * @return bool
+     */
+    public function isIssued()
+    {
+        return $this->status === SalesInvoiceStatus::ISSUED;
+    }
+
+    /**
+     * Returns whether the sales invoice is paid.
+     *
+     * @return bool
+     */
+    public function isPaid()
+    {
+        return $this->status === SalesInvoiceStatus::PAID;
+    }
+}
diff --git a/src/Resources/SalesInvoiceCollection.php b/src/Resources/SalesInvoiceCollection.php
new file mode 100644
index 00000000..4123f8b8
--- /dev/null
+++ b/src/Resources/SalesInvoiceCollection.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Mollie\Api\Resources;
+
+class SalesInvoiceCollection extends CursorCollection
+{
+    /**
+     * The name of the collection resource in Mollie's API.
+     */
+    public static string $collectionName = 'sales_invoices';
+
+    /**
+     * Resource class name.
+     */
+    public static string $resource = SalesInvoice::class;
+}
diff --git a/src/Traits/HasEndpoints.php b/src/Traits/HasEndpoints.php
index b13f653f..22d339a0 100644
--- a/src/Traits/HasEndpoints.php
+++ b/src/Traits/HasEndpoints.php
@@ -38,6 +38,7 @@
 use Mollie\Api\EndpointCollection\SubscriptionPaymentEndpointCollection;
 use Mollie\Api\EndpointCollection\TerminalEndpointCollection;
 use Mollie\Api\EndpointCollection\WalletEndpointCollection;
+use Mollie\Api\EndpointCollection\SalesInvoiceEndpointCollection;
 use Mollie\Api\MollieApiClient;
 
 /**
@@ -82,6 +83,7 @@ protected function initializeHasEndpoints(): void
             'profiles' => ProfileEndpointCollection::class,
             'profileMethods' => ProfileMethodEndpointCollection::class,
             'refunds' => RefundEndpointCollection::class,
+            'salesInvoices' => SalesInvoiceEndpointCollection::class,
             'sessions' => SessionEndpointCollection::class,
             'settlementCaptures' => SettlementCaptureEndpointCollection::class,
             'settlementChargebacks' => SettlementChargebackEndpointCollection::class,
diff --git a/src/Types/PaymentTerm.php b/src/Types/PaymentTerm.php
new file mode 100644
index 00000000..9b9e4372
--- /dev/null
+++ b/src/Types/PaymentTerm.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace Mollie\Api\Types;
+
+class PaymentTerm
+{
+    const DAYS_7 = '7 days';
+    const DAYS_14 = '14 days';
+    const DAYS_30 = '30 days';
+    const DAYS_45 = '45 days';
+    const DAYS_60 = '60 days';
+    const DAYS_90 = '90 days';
+    const DAYS_120 = '120 days';
+}
diff --git a/src/Types/RecipientType.php b/src/Types/RecipientType.php
new file mode 100644
index 00000000..c6befc02
--- /dev/null
+++ b/src/Types/RecipientType.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Mollie\Api\Types;
+
+class RecipientType
+{
+    const CONSUMER = 'consumer';
+    const BUSINESS = 'business';
+}
diff --git a/src/Types/SalesInvoiceStatus.php b/src/Types/SalesInvoiceStatus.php
new file mode 100644
index 00000000..02dc1369
--- /dev/null
+++ b/src/Types/SalesInvoiceStatus.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Mollie\Api\Types;
+
+class SalesInvoiceStatus
+{
+    /**
+     * The sales invoice is in draft status and has not been sent or paid.
+     */
+    const DRAFT = 'draft';
+
+    /**
+     * The sales invoice has been issued to the customer but has not been paid yet.
+     */
+    const ISSUED = 'issued';
+
+    /**
+     * The sales invoice has been fully paid.
+     */
+    const PAID = 'paid';
+}
diff --git a/src/Types/VatMode.php b/src/Types/VatMode.php
new file mode 100644
index 00000000..4178502b
--- /dev/null
+++ b/src/Types/VatMode.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Mollie\Api\Types;
+
+class VatMode
+{
+    const EXCLUSIVE = 'exclusive';
+    const INCLUSIVE = 'inclusive';
+}
diff --git a/src/Types/VatScheme.php b/src/Types/VatScheme.php
new file mode 100644
index 00000000..f331c17b
--- /dev/null
+++ b/src/Types/VatScheme.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Mollie\Api\Types;
+
+class VatScheme
+{
+    const STANDARD = 'standard';
+    const ONE_STOP_SHOP = 'one-stop-shop';
+}
diff --git a/tests/EndpointCollection/SalesInvoiceEndpointCollectionTest.php b/tests/EndpointCollection/SalesInvoiceEndpointCollectionTest.php
new file mode 100644
index 00000000..8886e132
--- /dev/null
+++ b/tests/EndpointCollection/SalesInvoiceEndpointCollectionTest.php
@@ -0,0 +1,136 @@
+<?php
+
+namespace Tests\EndpointCollection;
+
+use Mollie\Api\Http\Payload\CreateSalesInvoicePayload;
+use Mollie\Api\Http\Payload\DataCollection;
+use Mollie\Api\Http\Payload\InvoiceLine;
+use Mollie\Api\Http\Payload\Money;
+use Mollie\Api\Http\Payload\Recipient;
+use Mollie\Api\Http\Payload\UpdateSalesInvoicePayload;
+use Mollie\Api\Http\Requests\CreateSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\DeleteSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\DynamicGetRequest;
+use Mollie\Api\Http\Requests\GetPaginatedSalesInvoicesRequest;
+use Mollie\Api\Http\Requests\GetSalesInvoiceRequest;
+use Mollie\Api\Http\Requests\UpdateSalesInvoiceRequest;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Resources\SalesInvoiceCollection;
+use Mollie\Api\Types\PaymentTerm;
+use Mollie\Api\Types\RecipientType;
+use Mollie\Api\Types\SalesInvoiceStatus;
+use Mollie\Api\Types\VatMode;
+use Mollie\Api\Types\VatScheme;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\TestCase;
+
+class SalesInvoiceEndpointCollectionTest extends TestCase
+{
+    /** @test */
+    public function get()
+    {
+        $client = new MockClient([
+            GetSalesInvoiceRequest::class => new MockResponse(200, 'sales-invoice'),
+        ]);
+
+        $salesInvoice = $client->salesInvoices->get('inv_123');
+
+        $this->assertInstanceOf(SalesInvoice::class, $salesInvoice);
+    }
+
+    /** @test */
+    public function create()
+    {
+        $client = new MockClient([
+            CreateSalesInvoiceRequest::class => new MockResponse(201, 'sales-invoice'),
+        ]);
+
+        $invoiceLines = [
+            new InvoiceLine(
+                'Monthly subscription fee',
+                1,
+                '21',
+                new Money('EUR', '10,00'),
+            )
+        ];
+
+        // Create a sales invoice
+        $payload = new CreateSalesInvoicePayload(
+            'EUR',
+            SalesInvoiceStatus::DRAFT,
+            VatScheme::STANDARD,
+            VatMode::INCLUSIVE,
+            PaymentTerm::DAYS_30,
+            'XXXXX',
+            new Recipient(
+                RecipientType::CONSUMER,
+                'darth@vader.deathstar',
+                'Sample Street 12b',
+                '2000 AA',
+                'Amsterdam',
+                'NL',
+                'nl_NL'
+            ),
+            new DataCollection($invoiceLines)
+        );
+
+        $salesInvoice = $client->salesInvoices->create($payload);
+
+        $this->assertInstanceOf(SalesInvoice::class, $salesInvoice);
+    }
+
+    /** @test */
+    public function update()
+    {
+        $client = new MockClient([
+            UpdateSalesInvoiceRequest::class => new MockResponse(200, 'sales-invoice'),
+        ]);
+
+        $payload = new UpdateSalesInvoicePayload(
+            SalesInvoiceStatus::PAID,
+            'XXXXX',
+        );
+        $salesInvoice = $client->salesInvoices->update('invoice_123', $payload);
+
+        $this->assertInstanceOf(SalesInvoice::class, $salesInvoice);
+    }
+
+    /** @test */
+    public function delete()
+    {
+        $client = new MockClient([
+            DeleteSalesInvoiceRequest::class => new MockResponse(204),
+        ]);
+
+        $client->salesInvoices->delete('invoice_123');
+
+        $this->assertTrue(true); // Test passes if no exception is thrown
+    }
+
+    /** @test */
+    public function page()
+    {
+        $client = new MockClient([
+            GetPaginatedSalesInvoicesRequest::class => new MockResponse(200, 'sales-invoice-list'),
+        ]);
+
+        $salesInvoices = $client->salesInvoices->page();
+
+        $this->assertInstanceOf(SalesInvoiceCollection::class, $salesInvoices);
+    }
+
+    /** @test */
+    public function iterate()
+    {
+        $client = new MockClient([
+            GetPaginatedSalesInvoicesRequest::class => new MockResponse(200, 'sales-invoice-list'),
+            DynamicGetRequest::class => new MockResponse(200, 'empty-list', 'sales_invoices'),
+        ]);
+
+        /** @var SalesInvoice $salesInvoice */
+        foreach ($client->salesInvoices->iterator() as $salesInvoice) {
+            $this->assertInstanceOf(SalesInvoice::class, $salesInvoice);
+        }
+    }
+}
diff --git a/tests/Fixtures/Responses/sales-invoice-list.json b/tests/Fixtures/Responses/sales-invoice-list.json
new file mode 100644
index 00000000..fdd397d2
--- /dev/null
+++ b/tests/Fixtures/Responses/sales-invoice-list.json
@@ -0,0 +1,83 @@
+{
+  "count": 1,
+  "_embedded": {
+    "sales_invoices": [
+      {
+        "resource": "sales-invoice",
+        "id": "invoice_4Y0eZitmBnQ6IDoMqZQKh",
+        "profileId": "pfl_QkEhN94Ba",
+        "invoiceNumber": null,
+        "currency": "EUR",
+        "status": "draft",
+        "vatScheme": "standard",
+        "paymentTerm": "30 days",
+        "recipientIdentifier": "123532354",
+        "recipient": {
+          "title": null,
+          "givenName": "Given",
+          "familyName": "Family",
+          "email": "given.family@mollie.com",
+          "phone": null,
+          "streetAndNumber": "Street 1",
+          "streetAdditional": null,
+          "postalCode": "1000 AA",
+          "city": "Amsterdam",
+          "region": null,
+          "country": "NL"
+        },
+        "lines": [
+          {
+            "description": "LEGO 4440 Forest Police Station",
+            "quantity": 1,
+            "vatRate": "21",
+            "unitPrice": {
+              "value": "89.00",
+              "currency": "EUR"
+            },
+            "discount": null
+          }
+        ],
+        "discount": null,
+        "amountDue": {
+          "value": "107.69",
+          "currency": "EUR"
+        },
+        "subtotalAmount": {
+          "value": "89.00",
+          "currency": "EUR"
+        },
+        "totalAmount": {
+          "value": "107.69",
+          "currency": "EUR"
+        },
+        "totalVatAmount": {
+          "value": "18.69",
+          "currency": "EUR"
+        },
+        "discountedSubtotalAmount": {
+          "value": "89.00",
+          "currency": "EUR"
+        },
+        "createdAt": "2024-10-03T10:47:38.457381+00:00",
+        "issuedAt": null,
+        "dueAt": null,
+        "memo": null
+      }
+    ]
+  },
+  "_links": {
+    "self": {
+      "href": "...",
+      "type": "application/hal+json"
+    },
+    "previous": null,
+    "next": {
+      "href": "https://api.mollie.com/v2/sales/invoices?from=invoice_4yUfQpbKnd2DUTouUdUwH&limit=5",
+      "type": "application/hal+json"
+    },
+    "documentation": {
+      "href": "...",
+      "type": "text/html"
+    }
+  }
+}
diff --git a/tests/Fixtures/Responses/sales-invoice.json b/tests/Fixtures/Responses/sales-invoice.json
new file mode 100644
index 00000000..bda9bba0
--- /dev/null
+++ b/tests/Fixtures/Responses/sales-invoice.json
@@ -0,0 +1,81 @@
+{
+  "resource": "sales-invoice",
+  "id": "invoice_4Y0eZitmBnQ6IDoMqZQKh",
+  "profileId": "pfl_QkEhN94Ba",
+  "invoiceNumber": null,
+  "currency": "EUR",
+  "status": "draft",
+  "vatScheme": "standard",
+  "paymentTerm": "30 days",
+  "recipientIdentifier": "123532354",
+  "recipient": {
+    "type": "consumer",
+    "title": null,
+    "givenName": "Given",
+    "familyName": "Family",
+    "email": "given.family@mollie.com",
+    "phone": null,
+    "streetAndNumber": "Street 1",
+    "streetAdditional": null,
+    "postalCode": "1000 AA",
+    "city": "Amsterdam",
+    "region": null,
+    "country": "NL",
+    "locale": "nl_NL"
+  },
+  "lines": [
+    {
+      "description": "LEGO 4440 Forest Police Station",
+      "quantity": 1,
+      "vatRate": "21",
+      "unitPrice": {
+        "value": "89.00",
+        "currency": "EUR"
+      },
+      "discount": null
+    }
+  ],
+  "discount": null,
+  "amountDue": {
+    "value": "107.69",
+    "currency": "EUR"
+  },
+  "subtotalAmount": {
+    "value": "89.00",
+    "currency": "EUR"
+  },
+  "totalAmount": {
+    "value": "107.69",
+    "currency": "EUR"
+  },
+  "totalVatAmount": {
+    "value": "18.69",
+    "currency": "EUR"
+  },
+  "discountedSubtotalAmount": {
+    "value": "89.00",
+    "currency": "EUR"
+  },
+  "createdAt": "2024-10-03T10:47:38.457381+00:00",
+  "issuedAt": null,
+  "dueAt": null,
+  "memo": null,
+  "_links": {
+    "self": {
+      "href": "...",
+      "type": "application/hal+json"
+    },
+    "invoicePayment": {
+      "href": "...",
+      "type": "application/hal+json"
+    },
+    "pdfLink": {
+      "href": "...",
+      "type": "application/hal+json"
+    },
+    "documentation": {
+      "href": "...",
+      "type": "text/html"
+    }
+  }
+}
diff --git a/tests/Http/Requests/CreateSalesInvoiceRequestTest.php b/tests/Http/Requests/CreateSalesInvoiceRequestTest.php
new file mode 100644
index 00000000..60f71ef5
--- /dev/null
+++ b/tests/Http/Requests/CreateSalesInvoiceRequestTest.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Tests\Http\Requests;
+
+use Mollie\Api\Http\Payload\CreateSalesInvoicePayload;
+use Mollie\Api\Http\Payload\DataCollection;
+use Mollie\Api\Http\Payload\InvoiceLine;
+use Mollie\Api\Http\Payload\Money;
+use Mollie\Api\Http\Payload\Recipient;
+use Mollie\Api\Http\Requests\CreateSalesInvoiceRequest;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Types\PaymentTerm;
+use Mollie\Api\Types\RecipientType;
+use Mollie\Api\Types\SalesInvoiceStatus;
+use Mollie\Api\Types\VatMode;
+use Mollie\Api\Types\VatScheme;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\TestCase;
+
+class CreateSalesInvoiceRequestTest extends TestCase
+{
+    /** @test */
+    public function it_creates_sales_invoice()
+    {
+        $client = new MockClient([
+            CreateSalesInvoiceRequest::class => new MockResponse(201, 'sales-invoice'),
+        ]);
+
+        $invoiceLines = [
+            new InvoiceLine(
+                'Monthly subscription fee',
+                1,
+                '21',
+                new Money('EUR', '10,00'),
+            )
+        ];
+
+        // Create a sales invoice
+        $payload = new CreateSalesInvoicePayload(
+            'EUR',
+            SalesInvoiceStatus::DRAFT,
+            VatScheme::STANDARD,
+            VatMode::INCLUSIVE,
+            PaymentTerm::DAYS_30,
+            'XXXXX',
+            new Recipient(
+                RecipientType::CONSUMER,
+                'darth@vader.deathstar',
+                'Sample Street 12b',
+                '2000 AA',
+                'Amsterdam',
+                'NL',
+                'nl_NL'
+            ),
+            new DataCollection($invoiceLines)
+        );
+        $request = new CreateSalesInvoiceRequest($payload);
+
+        /** @var Response */
+        $response = $client->send($request);
+
+        $this->assertTrue($response->successful());
+        $this->assertInstanceOf(SalesInvoice::class, $response->toResource());
+    }
+
+    /** @test */
+    public function it_resolves_correct_resource_path()
+    {
+        $request = new CreateSalesInvoiceRequest(new CreateSalesInvoicePayload(
+            'EUR',
+            SalesInvoiceStatus::DRAFT,
+            VatScheme::STANDARD,
+            VatMode::INCLUSIVE,
+            PaymentTerm::DAYS_30,
+            'XXXXX',
+            new Recipient(
+                RecipientType::CONSUMER,
+                'darth@vader.deathstar',
+                'Sample Street 12b',
+                '2000 AA',
+                'Amsterdam',
+                'NL',
+                'nl_NL'
+            ),
+            new DataCollection([
+                new InvoiceLine(
+                    'Monthly subscription fee',
+                    1,
+                    '21',
+                    new Money('EUR', '10,00'),
+                )
+            ])
+        ));
+
+        $this->assertEquals('sales-invoices', $request->resolveResourcePath());
+    }
+}
diff --git a/tests/Http/Requests/DeleteSalesInvoiceRequestTest.php b/tests/Http/Requests/DeleteSalesInvoiceRequestTest.php
new file mode 100644
index 00000000..dfa4397b
--- /dev/null
+++ b/tests/Http/Requests/DeleteSalesInvoiceRequestTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Tests\Http\Requests;
+
+use Mollie\Api\Http\Requests\DeleteSalesInvoiceRequest;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\TestCase;
+
+class DeleteSalesInvoiceRequestTest extends TestCase
+{
+    /** @test */
+    public function it_deletes_sales_invoice()
+    {
+        $client = new MockClient([
+            DeleteSalesInvoiceRequest::class => new MockResponse(204),
+        ]);
+
+        $request = new DeleteSalesInvoiceRequest('invoice_123');
+
+        /** @var Response */
+        $response = $client->send($request);
+
+        $this->assertTrue($response->successful());
+        $this->assertEquals(204, $response->status());
+    }
+
+    /** @test */
+    public function it_resolves_correct_resource_path()
+    {
+        $request = new DeleteSalesInvoiceRequest('invoice_123');
+        $this->assertEquals('sales-invoices/invoice_123', $request->resolveResourcePath());
+    }
+}
diff --git a/tests/Http/Requests/GetPaginatedSalesInvoicesRequestTest.php b/tests/Http/Requests/GetPaginatedSalesInvoicesRequestTest.php
new file mode 100644
index 00000000..399741e9
--- /dev/null
+++ b/tests/Http/Requests/GetPaginatedSalesInvoicesRequestTest.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Tests\Http\Requests;
+
+use Mollie\Api\Http\Requests\DynamicGetRequest;
+use Mollie\Api\Http\Requests\GetPaginatedSalesInvoicesRequest;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Resources\SalesInvoiceCollection;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\Fixtures\SequenceMockResponse;
+use Tests\TestCase;
+
+class GetPaginatedSalesInvoicesRequestTest extends TestCase
+{
+    /** @test */
+    public function it_gets_paginated_sales_invoices()
+    {
+        $client = new MockClient([
+            GetPaginatedSalesInvoicesRequest::class => new MockResponse(200, 'sales-invoice-list'),
+        ]);
+
+        $request = new GetPaginatedSalesInvoicesRequest;
+
+        /** @var Response */
+        $response = $client->send($request);
+
+        $this->assertTrue($response->successful());
+
+        /** @var SalesInvoiceCollection */
+        $salesInvoices = $response->toResource();
+        $this->assertInstanceOf(SalesInvoiceCollection::class, $salesInvoices);
+        $this->assertGreaterThan(0, $salesInvoices->count());
+    }
+
+    /** @test */
+    public function it_can_iterate_over_sales_invoices()
+    {
+        $client = new MockClient([
+            GetPaginatedSalesInvoicesRequest::class => new MockResponse(200, 'sales-invoice-list'),
+            DynamicGetRequest::class => new SequenceMockResponse(
+                new MockResponse(200, 'sales-invoice-list'),
+                new MockResponse(200, 'empty-list', 'sales_invoices'),
+            ),
+        ]);
+
+        $request = (new GetPaginatedSalesInvoicesRequest)->useIterator();
+
+        /** @var Response */
+        $response = $client->send($request);
+        $this->assertTrue($response->successful());
+
+        /** @var LazyCollection */
+        $salesInvoices = $response->toResource();
+
+        foreach ($salesInvoices as $salesInvoice) {
+            $this->assertInstanceOf(SalesInvoice::class, $salesInvoice);
+        }
+
+        $client->assertSentCount(3);
+    }
+
+    /** @test */
+    public function it_resolves_correct_resource_path()
+    {
+        $request = new GetPaginatedSalesInvoicesRequest;
+        $this->assertEquals('sales-invoices', $request->resolveResourcePath());
+    }
+}
diff --git a/tests/Http/Requests/GetSalesInvoiceRequestTest.php b/tests/Http/Requests/GetSalesInvoiceRequestTest.php
new file mode 100644
index 00000000..b38fc655
--- /dev/null
+++ b/tests/Http/Requests/GetSalesInvoiceRequestTest.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Tests\Http\Requests;
+
+use Mollie\Api\Http\Requests\GetSalesInvoiceRequest;
+use Mollie\Api\Resources\SalesInvoice;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\TestCase;
+
+class GetSalesInvoiceRequestTest extends TestCase
+{
+    /** @test */
+    public function it_fetches_sales_invoice()
+    {
+        $client = new MockClient([
+            GetSalesInvoiceRequest::class => new MockResponse(200, 'sales-invoice'),
+        ]);
+
+        $request = new GetSalesInvoiceRequest('invoice_123');
+        $response = $client->send($request);
+
+        $this->assertTrue($response->successful());
+        $this->assertInstanceOf(SalesInvoice::class, $response->toResource());
+    }
+}
diff --git a/tests/Http/Requests/UpdateSalesInvoiceRequestTest.php b/tests/Http/Requests/UpdateSalesInvoiceRequestTest.php
new file mode 100644
index 00000000..a58b65ae
--- /dev/null
+++ b/tests/Http/Requests/UpdateSalesInvoiceRequestTest.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Tests\Http\Requests;
+
+use Mollie\Api\Http\Payload\UpdateSalesInvoicePayload;
+use Mollie\Api\Http\Requests\UpdateSalesInvoiceRequest;
+use Mollie\Api\Resources\SalesInvoice;
+use Mollie\Api\Types\SalesInvoiceStatus;
+use Tests\Fixtures\MockClient;
+use Tests\Fixtures\MockResponse;
+use Tests\TestCase;
+
+class UpdateSalesInvoiceRequestTest extends TestCase
+{
+    /** @test */
+    public function it_updates_sales_invoice()
+    {
+        $client = new MockClient([
+            UpdateSalesInvoiceRequest::class => new MockResponse(200, 'sales-invoice'),
+        ]);
+
+        $payload = new UpdateSalesInvoicePayload(
+            SalesInvoiceStatus::PAID,
+            'XXXXX',
+        );
+        $request = new UpdateSalesInvoiceRequest('invoice_123', $payload);
+
+        /** @var Response */
+        $response = $client->send($request);
+
+        $this->assertTrue($response->successful());
+        $this->assertInstanceOf(SalesInvoice::class, $response->toResource());
+    }
+
+    /** @test */
+    public function it_resolves_correct_resource_path()
+    {
+        $request = new UpdateSalesInvoiceRequest('invoice_123', new UpdateSalesInvoicePayload(
+            SalesInvoiceStatus::PAID,
+            'XXXXX',
+        ));
+        $this->assertEquals('sales-invoices/invoice_123', $request->resolveResourcePath());
+    }
+}