diff --git a/src/Notifications/API/Models/EmailContentTypeExt.cs b/src/Notifications/API/Models/EmailContentTypeExt.cs
index 76cca39c..22921275 100644
--- a/src/Notifications/API/Models/EmailContentTypeExt.cs
+++ b/src/Notifications/API/Models/EmailContentTypeExt.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Models;
+#nullable enable
+namespace Altinn.Notifications.Models;
 
 /// <summary>
 /// Enum describing available content types for an email.
diff --git a/src/Notifications/API/Models/EmailNotificationWithResultExt.cs b/src/Notifications/API/Models/EmailNotificationWithResultExt.cs
index 49922d59..2e664978 100644
--- a/src/Notifications/API/Models/EmailNotificationWithResultExt.cs
+++ b/src/Notifications/API/Models/EmailNotificationWithResultExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 using Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/EmailTemplateExt.cs b/src/Notifications/API/Models/EmailTemplateExt.cs
index ad5a2d88..8e2c40c4 100644
--- a/src/Notifications/API/Models/EmailTemplateExt.cs
+++ b/src/Notifications/API/Models/EmailTemplateExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/NotificationChannelExt.cs b/src/Notifications/API/Models/NotificationChannelExt.cs
index 1510efab..11bea3a2 100644
--- a/src/Notifications/API/Models/NotificationChannelExt.cs
+++ b/src/Notifications/API/Models/NotificationChannelExt.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Models;
+#nullable enable
+namespace Altinn.Notifications.Models;
 
 /// <summary>
 /// Enum describing available notification channels.
diff --git a/src/Notifications/API/Models/NotificationOrderListExt.cs b/src/Notifications/API/Models/NotificationOrderListExt.cs
index ba315592..e21362ae 100644
--- a/src/Notifications/API/Models/NotificationOrderListExt.cs
+++ b/src/Notifications/API/Models/NotificationOrderListExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/NotificationResourceLinksExt.cs b/src/Notifications/API/Models/NotificationResourceLinksExt.cs
index e4cd97fc..72376c2d 100644
--- a/src/Notifications/API/Models/NotificationResourceLinksExt.cs
+++ b/src/Notifications/API/Models/NotificationResourceLinksExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/NotificationStatusExt.cs b/src/Notifications/API/Models/NotificationStatusExt.cs
index b8dc8b42..bb2bb54d 100644
--- a/src/Notifications/API/Models/NotificationStatusExt.cs
+++ b/src/Notifications/API/Models/NotificationStatusExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/OrderIdExt.cs b/src/Notifications/API/Models/OrderIdExt.cs
index c615b718..551e574e 100644
--- a/src/Notifications/API/Models/OrderIdExt.cs
+++ b/src/Notifications/API/Models/OrderIdExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Models/OrderResourceLinksExt.cs b/src/Notifications/API/Models/OrderResourceLinksExt.cs
index 07d0e80d..843f44ec 100644
--- a/src/Notifications/API/Models/OrderResourceLinksExt.cs
+++ b/src/Notifications/API/Models/OrderResourceLinksExt.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 namespace Altinn.Notifications.Models;
 
diff --git a/src/Notifications/API/Controllers/EmailNotificationOrderRequestValidator.cs b/src/Notifications/API/Validators/EmailNotificationOrderRequestValidator.cs
similarity index 100%
rename from src/Notifications/API/Controllers/EmailNotificationOrderRequestValidator.cs
rename to src/Notifications/API/Validators/EmailNotificationOrderRequestValidator.cs
diff --git a/src/Notifications/API/Controllers/ValidationResultExtensions.cs b/src/Notifications/API/Validators/ValidationResultExtensions.cs
similarity index 91%
rename from src/Notifications/API/Controllers/ValidationResultExtensions.cs
rename to src/Notifications/API/Validators/ValidationResultExtensions.cs
index e5816351..18ffe907 100644
--- a/src/Notifications/API/Controllers/ValidationResultExtensions.cs
+++ b/src/Notifications/API/Validators/ValidationResultExtensions.cs
@@ -1,4 +1,5 @@
-using FluentValidation.Results;
+#nullable enable
+using FluentValidation.Results;
 
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 
diff --git a/src/Notifications/Core/Enums/AddressType.cs b/src/Notifications/Core/Enums/AddressType.cs
index 884ec380..caf5ca9a 100644
--- a/src/Notifications/Core/Enums/AddressType.cs
+++ b/src/Notifications/Core/Enums/AddressType.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 #pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
 /// <summary>
diff --git a/src/Notifications/Core/Enums/EmailContentType.cs b/src/Notifications/Core/Enums/EmailContentType.cs
index ad3b5c53..991ae849 100644
--- a/src/Notifications/Core/Enums/EmailContentType.cs
+++ b/src/Notifications/Core/Enums/EmailContentType.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 /// <summary>
 /// Enum describing available email content types
diff --git a/src/Notifications/Core/Enums/EmailNotificationResultType.cs b/src/Notifications/Core/Enums/EmailNotificationResultType.cs
index 65813841..28e0562d 100644
--- a/src/Notifications/Core/Enums/EmailNotificationResultType.cs
+++ b/src/Notifications/Core/Enums/EmailNotificationResultType.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 /// <summary>
 /// Enum describing email notification result types
diff --git a/src/Notifications/Core/Enums/IResultType.cs b/src/Notifications/Core/Enums/IResultType.cs
index b74d0b50..d8dea4d1 100644
--- a/src/Notifications/Core/Enums/IResultType.cs
+++ b/src/Notifications/Core/Enums/IResultType.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 /// <summary>
 /// Base class for send result of a notification
diff --git a/src/Notifications/Core/Enums/NotificationChannel.cs b/src/Notifications/Core/Enums/NotificationChannel.cs
index 7da282be..4e23d060 100644
--- a/src/Notifications/Core/Enums/NotificationChannel.cs
+++ b/src/Notifications/Core/Enums/NotificationChannel.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 /// <summary>
 /// Enum describing available notification channels.
diff --git a/src/Notifications/Core/Enums/NotificationTemplateType.cs b/src/Notifications/Core/Enums/NotificationTemplateType.cs
index ae0de091..a7e02909 100644
--- a/src/Notifications/Core/Enums/NotificationTemplateType.cs
+++ b/src/Notifications/Core/Enums/NotificationTemplateType.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 #pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
 /// <summary>
diff --git a/src/Notifications/Core/Enums/OrderProcessingStatus.cs b/src/Notifications/Core/Enums/OrderProcessingStatus.cs
index 757bb44f..20c22fa9 100644
--- a/src/Notifications/Core/Enums/OrderProcessingStatus.cs
+++ b/src/Notifications/Core/Enums/OrderProcessingStatus.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Enums;
+#nullable enable
+namespace Altinn.Notifications.Core.Enums;
 
 #pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
 /// <summary>
diff --git a/src/Notifications/Core/Models/Address/EmailAddressPoint.cs b/src/Notifications/Core/Models/Address/EmailAddressPoint.cs
index 9e720b1b..aa2b3031 100644
--- a/src/Notifications/Core/Models/Address/EmailAddressPoint.cs
+++ b/src/Notifications/Core/Models/Address/EmailAddressPoint.cs
@@ -1,4 +1,5 @@
-using Altinn.Notifications.Core.Enums;
+#nullable enable
+using Altinn.Notifications.Core.Enums;
 
 namespace Altinn.Notifications.Core.Models.Address;
 
diff --git a/src/Notifications/Core/Models/Address/IAddressPoint.cs b/src/Notifications/Core/Models/Address/IAddressPoint.cs
index fd961f02..e15ccc17 100644
--- a/src/Notifications/Core/Models/Address/IAddressPoint.cs
+++ b/src/Notifications/Core/Models/Address/IAddressPoint.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 using Altinn.Notifications.Core.Enums;
 
diff --git a/src/Notifications/Core/Models/Creator.cs b/src/Notifications/Core/Models/Creator.cs
index 794e1d0c..ef0e334a 100644
--- a/src/Notifications/Core/Models/Creator.cs
+++ b/src/Notifications/Core/Models/Creator.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Models;
+#nullable enable
+namespace Altinn.Notifications.Core.Models;
 
 /// <summary>
 /// A class representing a notification creator 
diff --git a/src/Notifications/Core/Models/Email.cs b/src/Notifications/Core/Models/Email.cs
index 4f86765d..00a3ecce 100644
--- a/src/Notifications/Core/Models/Email.cs
+++ b/src/Notifications/Core/Models/Email.cs
@@ -1,4 +1,5 @@
-using System.Text.Json;
+#nullable enable
+using System.Text.Json;
 using System.Text.Json.Serialization;
 
 using Altinn.Notifications.Core.Enums;
diff --git a/src/Notifications/Core/Models/Notification/EmailNotificationWithResult.cs b/src/Notifications/Core/Models/Notification/EmailNotificationWithResult.cs
index 23146430..a8c7e851 100644
--- a/src/Notifications/Core/Models/Notification/EmailNotificationWithResult.cs
+++ b/src/Notifications/Core/Models/Notification/EmailNotificationWithResult.cs
@@ -1,4 +1,5 @@
-using Altinn.Notifications.Core.Enums;
+#nullable enable
+using Altinn.Notifications.Core.Enums;
 using Altinn.Notifications.Core.Models.Recipients;
 
 namespace Altinn.Notifications.Core.Models.Notification
diff --git a/src/Notifications/Core/Models/Notification/INotification.cs b/src/Notifications/Core/Models/Notification/INotification.cs
index ab244642..4bee1b10 100644
--- a/src/Notifications/Core/Models/Notification/INotification.cs
+++ b/src/Notifications/Core/Models/Notification/INotification.cs
@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 
 using Altinn.Notifications.Core.Enums;
 
diff --git a/src/Notifications/Core/Models/Notification/INotificationWithResult.cs b/src/Notifications/Core/Models/Notification/INotificationWithResult.cs
index 0ddfa3bb..aa95da12 100644
--- a/src/Notifications/Core/Models/Notification/INotificationWithResult.cs
+++ b/src/Notifications/Core/Models/Notification/INotificationWithResult.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Models.Notification;
+#nullable enable
+namespace Altinn.Notifications.Core.Models.Notification;
 
 /// <summary>
 /// Interface representing a notification object with send result data
diff --git a/src/Notifications/Core/Models/NotificationTemplate/INotificationTemplate.cs b/src/Notifications/Core/Models/NotificationTemplate/INotificationTemplate.cs
index c8f3ce71..106efd09 100644
--- a/src/Notifications/Core/Models/NotificationTemplate/INotificationTemplate.cs
+++ b/src/Notifications/Core/Models/NotificationTemplate/INotificationTemplate.cs
@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+#nullable enable
+using System.Text.Json.Serialization;
 
 using Altinn.Notifications.Core.Enums;
 
diff --git a/src/Notifications/Core/Models/Recipient.cs b/src/Notifications/Core/Models/Recipient.cs
index c46f5712..c0517c41 100644
--- a/src/Notifications/Core/Models/Recipient.cs
+++ b/src/Notifications/Core/Models/Recipient.cs
@@ -1,4 +1,5 @@
-using Altinn.Notifications.Core.Models.Address;
+#nullable enable
+using Altinn.Notifications.Core.Models.Address;
 
 namespace Altinn.Notifications.Core.Models;
 
diff --git a/src/Notifications/Core/Repository/IOrderRepository.cs b/src/Notifications/Core/Repository/Interfaces/IOrderRepository.cs
similarity index 100%
rename from src/Notifications/Core/Repository/IOrderRepository.cs
rename to src/Notifications/Core/Repository/Interfaces/IOrderRepository.cs
diff --git a/src/Notifications/Core/Services/DateTimeService.cs b/src/Notifications/Core/Services/DateTimeService.cs
index b78bf5e7..a48321cd 100644
--- a/src/Notifications/Core/Services/DateTimeService.cs
+++ b/src/Notifications/Core/Services/DateTimeService.cs
@@ -1,4 +1,5 @@
-using System.Diagnostics.CodeAnalysis;
+#nullable enable
+using System.Diagnostics.CodeAnalysis;
 
 using Altinn.Notifications.Core.Services.Interfaces;
 
diff --git a/src/Notifications/Core/Services/GuidService.cs b/src/Notifications/Core/Services/GuidService.cs
index e106fbd3..d6614803 100644
--- a/src/Notifications/Core/Services/GuidService.cs
+++ b/src/Notifications/Core/Services/GuidService.cs
@@ -1,4 +1,5 @@
-using System.Diagnostics.CodeAnalysis;
+#nullable enable
+using System.Diagnostics.CodeAnalysis;
 
 using Altinn.Notifications.Core.Services.Interfaces;
 
diff --git a/src/Notifications/Core/Services/Interfaces/IDateTimeService.cs b/src/Notifications/Core/Services/Interfaces/IDateTimeService.cs
index 9cdae256..8ff6b2b1 100644
--- a/src/Notifications/Core/Services/Interfaces/IDateTimeService.cs
+++ b/src/Notifications/Core/Services/Interfaces/IDateTimeService.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Services.Interfaces;
+#nullable enable
+namespace Altinn.Notifications.Core.Services.Interfaces;
 
 /// <summary>
 /// Interface describing a dateTime service
diff --git a/src/Notifications/Core/Services/Interfaces/IGuidService.cs b/src/Notifications/Core/Services/Interfaces/IGuidService.cs
index 04b70707..16b81efc 100644
--- a/src/Notifications/Core/Services/Interfaces/IGuidService.cs
+++ b/src/Notifications/Core/Services/Interfaces/IGuidService.cs
@@ -1,4 +1,5 @@
-namespace Altinn.Notifications.Core.Services.Interfaces;
+#nullable enable
+namespace Altinn.Notifications.Core.Services.Interfaces;
 
 /// <summary>
 /// Interface describing a guid service
diff --git a/src/Notifications/Persistence/Repository/OrderRepository.cs b/src/Notifications/Persistence/Repository/OrderRepository.cs
index f9e956cb..2f64ae9d 100644
--- a/src/Notifications/Persistence/Repository/OrderRepository.cs
+++ b/src/Notifications/Persistence/Repository/OrderRepository.cs
@@ -1,4 +1,5 @@
-using System.Text.Json;
+#nullable enable
+using System.Text.Json;
 
 using Altinn.Notifications.Core.Enums;
 using Altinn.Notifications.Core.Models.Orders;