diff --git a/.eslintignore b/.eslintignore
new file mode 100644
index 0000000..f1ff06d
--- /dev/null
+++ b/.eslintignore
@@ -0,0 +1 @@
+lib/
\ No newline at end of file
diff --git a/lib/index.d.ts b/lib/index.d.ts
index 5afd9b1..2ce63c8 100644
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -1,21 +1,21 @@
-export { DbCalculation } from "./models/directbilling/service/db.calculation";
-export { DbProvider, DbProviderID } from "./models/directbilling/db.provider";
-export { DbService, DbServiceNotify } from "./models/directbilling/service/db.service";
-export { PartialDbService } from "./models/directbilling/service/partial.db.service";
-export { DbGenerationResponse } from "./models/directbilling/transaction/db.generation.response";
-export { DbTransactionRequest } from "./models/directbilling/transaction/db.transaction.request";
-export { DbTransactionStatus } from "./models/directbilling/transaction/db.transaction.status";
-export { DbTransaction } from "./models/directbilling/transaction/db.transaction";
-export { PartialDbTransaction } from "./models/directbilling/transaction/partial.db.transaction";
-export { DBServiceStatus } from "./models/directbilling/service/db.service.status";
-export { PaginatedResponse } from "./models/response/paginated.response";
-export { AmountType } from "./models/amount.type";
-export { SmsNumber } from "./models/sms/service/sms.number";
-export { SmsService } from "./models/sms/service/sms.service";
-export { SmsServiceType } from "./models/sms/service/sms.service.type";
-export { SmsTransaction } from "./models/sms/transaction/sms.transaction";
-export { VerificationResponse } from "./models/sms/verification.response";
-export { SMSServiceStatus } from "./models/sms/service/sms.service.status";
-export { DirectBilling } from "./payments/directbilling";
-export { Sms } from "./payments/sms";
-export { SmsXml } from "./payments/sms.xml";
+export { DbCalculation } from './models/directbilling/service/db.calculation';
+export { DbProvider, DbProviderID } from './models/directbilling/db.provider';
+export { DbService, DbServiceNotify } from './models/directbilling/service/db.service';
+export { PartialDbService } from './models/directbilling/service/partial.db.service';
+export { DbGenerationResponse } from './models/directbilling/transaction/db.generation.response';
+export { DbTransactionRequest } from './models/directbilling/transaction/db.transaction.request';
+export { DbTransactionStatus } from './models/directbilling/transaction/db.transaction.status';
+export { DbTransaction } from './models/directbilling/transaction/db.transaction';
+export { PartialDbTransaction } from './models/directbilling/transaction/partial.db.transaction';
+export { DBServiceStatus } from './models/directbilling/service/db.service.status';
+export { PaginatedResponse } from './models/response/paginated.response';
+export { AmountType } from './models/amount.type';
+export { SmsNumber } from './models/sms/service/sms.number';
+export { SmsService } from './models/sms/service/sms.service';
+export { SmsServiceType } from './models/sms/service/sms.service.type';
+export { SmsTransaction } from './models/sms/transaction/sms.transaction';
+export { VerificationResponse } from './models/sms/verification.response';
+export { SMSServiceStatus } from './models/sms/service/sms.service.status';
+export { DirectBilling } from './payments/directbilling';
+export { Sms } from './payments/sms';
+export { SmsXml } from './payments/sms.xml';
diff --git a/lib/models/directbilling/transaction/db.notifications.request.d.ts b/lib/models/directbilling/transaction/db.notifications.request.d.ts
index acb719c..9e87508 100644
--- a/lib/models/directbilling/transaction/db.notifications.request.d.ts
+++ b/lib/models/directbilling/transaction/db.notifications.request.d.ts
@@ -3,7 +3,7 @@ import { DbTransactionStatus } from '../transaction/db.transaction.status';
 import { DbProviderID } from '../db.provider';
 export interface DbNotificationRequest {
     id: string;
-    service_id: number;
+    service_id: string;
     status: DbTransactionStatus;
     values?: {
         net?: number;
diff --git a/lib/models/sms/service/sms.service.d.ts b/lib/models/sms/service/sms.service.d.ts
index d1f8b63..79cf0f2 100644
--- a/lib/models/sms/service/sms.service.d.ts
+++ b/lib/models/sms/service/sms.service.d.ts
@@ -1,7 +1,7 @@
 import { SmsServiceType } from './sms.service.type';
 import { SMSServiceStatus } from './sms.service.status';
 export interface SmsService {
-    id: number;
+    id: string;
     type: SmsServiceType;
     status: SMSServiceStatus;
     name: string;
diff --git a/lib/payments/directbilling.d.ts b/lib/payments/directbilling.d.ts
index 4bedd86..8f768fe 100644
--- a/lib/payments/directbilling.d.ts
+++ b/lib/payments/directbilling.d.ts
@@ -14,12 +14,12 @@ export declare class DirectBilling {
     constructor(key: string, password: string);
     getServices(): Promise<PartialDbService[]>;
     getServicesPaginated(page?: number, pageSize?: number): Promise<PaginatedResponse<PartialDbService>>;
-    getService(id: number): Promise<DbService | undefined>;
-    calculateCommission(serviceId: number, amount: number): Promise<DbCalculation | undefined>;
-    getTransactions(serviceId: number): Promise<PartialDbTransaction[]>;
-    getTransactionsPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<PartialDbTransaction>>;
-    getTransaction(serviceId: number, transactionId: string): Promise<DbTransaction | undefined>;
-    createTransaction(serviceId: number, key: string, request: DbTransactionRequest): Promise<DbGenerationResponse | undefined>;
+    getService(id: string): Promise<DbService | undefined>;
+    calculateCommission(serviceId: string, amount: number): Promise<DbCalculation | undefined>;
+    getTransactions(serviceId: string): Promise<PartialDbTransaction[]>;
+    getTransactionsPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<PartialDbTransaction>>;
+    getTransaction(serviceId: string, transactionId: string): Promise<DbTransaction | undefined>;
+    createTransaction(serviceId: string, key: string, request: DbTransactionRequest): Promise<DbGenerationResponse | undefined>;
     checkNotification(key: string, body: any): DbNotificationRequest | undefined;
     generateSignature(key: string, request: DbTransactionRequest): string;
     generateSignatureNotification(key: string, request: DbNotificationRequest): string;
diff --git a/lib/payments/sms.d.ts b/lib/payments/sms.d.ts
index 7b08c97..6a401b1 100644
--- a/lib/payments/sms.d.ts
+++ b/lib/payments/sms.d.ts
@@ -10,15 +10,15 @@ export declare class Sms {
     constructor(key: string, password: string);
     getServices(): Promise<SmsService[]>;
     getServicesPaginated(page?: number, pageSize?: number): Promise<PaginatedResponse<SmsService>>;
-    getService(id: number): Promise<SmsService | undefined>;
-    getTransactions(serviceId: number): Promise<SmsTransaction[]>;
-    getTransactionsPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsTransaction>>;
-    getTransaction(serviceId: number, transactionId: number): Promise<SmsTransaction | undefined>;
-    getServiceNumbers(serviceId: number): Promise<SmsNumber[]>;
-    getServiceNumbersPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsNumber>>;
-    getServiceNumber(serviceId: number, number: number): Promise<SmsNumber>;
+    getService(id: string): Promise<SmsService | undefined>;
+    getTransactions(serviceId: string): Promise<SmsTransaction[]>;
+    getTransactionsPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsTransaction>>;
+    getTransaction(serviceId: string, transactionId: number): Promise<SmsTransaction | undefined>;
+    getServiceNumbers(serviceId: string): Promise<SmsNumber[]>;
+    getServiceNumbersPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsNumber>>;
+    getServiceNumber(serviceId: string, number: number): Promise<SmsNumber>;
     getNumbers(): Promise<SmsNumber[]>;
     getNumbersPaginated(page?: number, pageSize?: number): Promise<PaginatedResponse<SmsNumber>>;
     getNumber(number: number): Promise<SmsNumber | undefined>;
-    verifySmsCode(serviceId: number, code: string, number?: number): Promise<VerificationResponse | undefined>;
+    verifySmsCode(serviceId: string, code: string, number?: number): Promise<VerificationResponse | undefined>;
 }
diff --git a/lib/tests/directbilling.js b/lib/tests/directbilling.js
index 034b250..39ab240 100644
--- a/lib/tests/directbilling.js
+++ b/lib/tests/directbilling.js
@@ -17,22 +17,22 @@ const run = () => __awaiter(void 0, void 0, void 0, function* () {
     console.log(yield db.getServices());
     console.log(yield db.getServicesPaginated(1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-usludze
-    console.log(yield db.getService(158));
+    console.log(yield db.getService('19f3b33c'));
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-kalkulacja-prowizji
-    console.log(yield db.calculateCommission(158, 10.00));
+    console.log(yield db.calculateCommission('19f3b33c', 10.00));
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-listy-transakcji
-    const transactionsList = yield db.getTransactions(158);
+    const transactionsList = yield db.getTransactions('19f3b33c');
     console.log(transactionsList);
-    console.log(yield db.getTransactionsPaginated(158, 1, 100));
+    console.log(yield db.getTransactionsPaginated('19f3b33c', 1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-transakcji
-    console.log(yield db.getTransaction(158, transactionsList === null || transactionsList === void 0 ? void 0 : transactionsList[0].id));
+    console.log(yield db.getTransaction('19f3b33c', transactionsList === null || transactionsList === void 0 ? void 0 : transactionsList[0].id));
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-generowanie-transakcji
-    console.log(yield db.createTransaction(158, 'key', {
+    console.log(yield db.createTransaction('19f3b33c', 'key', {
         amount: 10.00,
         amountType: amount_type_1.AmountType.GROSS,
         control: 'test'
     }));
-    console.log(yield db.checkNotification('key', {}));
+    console.log(db.checkNotification('key', {}));
 });
 // eslint-disable-next-line @typescript-eslint/no-empty-function
 void run();
diff --git a/lib/tests/sms.js b/lib/tests/sms.js
index de1fea3..88d3ca6 100644
--- a/lib/tests/sms.js
+++ b/lib/tests/sms.js
@@ -16,25 +16,25 @@ const run = () => __awaiter(void 0, void 0, void 0, function* () {
     console.log(yield sms.getServices());
     console.log(yield sms.getServicesPaginated(1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-usludze
-    console.log(yield sms.getService(3549));
+    console.log(yield sms.getService('d151e4f9'));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-listy-transakcji
-    console.log(yield sms.getTransactions(3549));
-    console.log(yield sms.getTransactionsPaginated(3549, 1, 100));
+    console.log(yield sms.getTransactions('d151e4f9'));
+    console.log(yield sms.getTransactionsPaginated('d151e4f9', 1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-transakcji
-    console.log(yield sms.getTransaction(3549, 2216609));
+    console.log(yield sms.getTransaction('d151e4f9', 2216609));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-dostepnych-numerow-dla-uslugi
-    console.log(yield sms.getServiceNumbers(3549));
-    console.log(yield sms.getServiceNumbersPaginated(3549, 1, 100));
+    console.log(yield sms.getServiceNumbers('d151e4f9'));
+    console.log(yield sms.getServiceNumbersPaginated('d151e4f9', 1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-informacji-o-pojedynczym-numerze-uslugi
-    console.log(yield sms.getServiceNumber(3549, 7055));
+    console.log(yield sms.getServiceNumber('d151e4f9', 7055));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-wszystkich-dostepnych-numerow
     console.log(yield sms.getNumbers());
     console.log(yield sms.getNumbersPaginated(1, 100));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-pojedynczego-numeru-sms
     console.log(yield sms.getNumber(7055));
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-weryfikacja-poprawnosci-kodu
-    console.log(yield sms.verifySmsCode(3549, '81FFC5', 7055));
-    console.log(yield sms.verifySmsCode(3549, '81FFC5'));
+    console.log(yield sms.verifySmsCode('d151e4f9', '81FFC5', 7055));
+    console.log(yield sms.verifySmsCode('d151e4f9', '81FFC5'));
 });
 // eslint-disable-next-line @typescript-eslint/no-empty-function
 void run();
diff --git a/package.json b/package.json
index c199fb4..5ab8498 100644
--- a/package.json
+++ b/package.json
@@ -1,14 +1,15 @@
 {
   "name": "simpay-typescript-api",
   "author": "Rafał Więcek",
-  "version": "2.2.4",
+  "version": "2.3.0",
   "description": "SimPay.pl API",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
     "build": "tsc",
-    "lint": "eslint",
+    "lint": "eslint .",
+    "lint:fix": "eslint --fix .",
     "dev": "tsc && node lib/test.js"
   },
   "keywords": [
diff --git a/src/index.ts b/src/index.ts
index b6bb515..fbc2f61 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,28 +1,28 @@
 // DirectBilling - Models
-export { DbCalculation } from "./models/directbilling/service/db.calculation";
-export { DbProvider, DbProviderID } from "./models/directbilling/db.provider";
-export { DbService, DbServiceNotify } from "./models/directbilling/service/db.service";
-export { PartialDbService } from "./models/directbilling/service/partial.db.service";
-export { DbGenerationResponse } from "./models/directbilling/transaction/db.generation.response";
-export { DbTransactionRequest } from "./models/directbilling/transaction/db.transaction.request";
-export { DbTransactionStatus } from "./models/directbilling/transaction/db.transaction.status";
-export { DbTransaction } from "./models/directbilling/transaction/db.transaction";
-export { PartialDbTransaction } from "./models/directbilling/transaction/partial.db.transaction";
-export { DBServiceStatus } from "./models/directbilling/service/db.service.status";
+export { DbCalculation } from './models/directbilling/service/db.calculation';
+export { DbProvider, DbProviderID } from './models/directbilling/db.provider';
+export { DbService, DbServiceNotify } from './models/directbilling/service/db.service';
+export { PartialDbService } from './models/directbilling/service/partial.db.service';
+export { DbGenerationResponse } from './models/directbilling/transaction/db.generation.response';
+export { DbTransactionRequest } from './models/directbilling/transaction/db.transaction.request';
+export { DbTransactionStatus } from './models/directbilling/transaction/db.transaction.status';
+export { DbTransaction } from './models/directbilling/transaction/db.transaction';
+export { PartialDbTransaction } from './models/directbilling/transaction/partial.db.transaction';
+export { DBServiceStatus } from './models/directbilling/service/db.service.status';
 
 // Response
-export { PaginatedResponse } from "./models/response/paginated.response";
-export { AmountType } from "./models/amount.type";
+export { PaginatedResponse } from './models/response/paginated.response';
+export { AmountType } from './models/amount.type';
 
 // SMS - Models
-export { SmsNumber } from "./models/sms/service/sms.number";
-export { SmsService } from "./models/sms/service/sms.service";
-export { SmsServiceType } from "./models/sms/service/sms.service.type";
-export { SmsTransaction } from "./models/sms/transaction/sms.transaction";
-export { VerificationResponse } from "./models/sms/verification.response";
-export { SMSServiceStatus } from "./models/sms/service/sms.service.status";
+export { SmsNumber } from './models/sms/service/sms.number';
+export { SmsService } from './models/sms/service/sms.service';
+export { SmsServiceType } from './models/sms/service/sms.service.type';
+export { SmsTransaction } from './models/sms/transaction/sms.transaction';
+export { VerificationResponse } from './models/sms/verification.response';
+export { SMSServiceStatus } from './models/sms/service/sms.service.status';
 
 // Payments
-export { DirectBilling } from "./payments/directbilling"
-export { Sms } from "./payments/sms"
-export { SmsXml } from "./payments/sms.xml"
\ No newline at end of file
+export { DirectBilling } from './payments/directbilling';
+export { Sms } from './payments/sms';
+export { SmsXml } from './payments/sms.xml';
\ No newline at end of file
diff --git a/src/models/directbilling/transaction/db.notifications.request.ts b/src/models/directbilling/transaction/db.notifications.request.ts
index 9297c11..f97d5eb 100644
--- a/src/models/directbilling/transaction/db.notifications.request.ts
+++ b/src/models/directbilling/transaction/db.notifications.request.ts
@@ -4,7 +4,7 @@ import {DbProviderID} from '../db.provider';
 
 export interface DbNotificationRequest {
     id: string,
-    service_id: number,
+    service_id: string,
     status: DbTransactionStatus,
     values?: {
         net?: number,
diff --git a/src/models/sms/service/sms.service.ts b/src/models/sms/service/sms.service.ts
index 42b29d2..dde9346 100644
--- a/src/models/sms/service/sms.service.ts
+++ b/src/models/sms/service/sms.service.ts
@@ -2,7 +2,7 @@ import {SmsServiceType} from './sms.service.type';
 import {SMSServiceStatus} from './sms.service.status';
 
 export interface SmsService {
-    id: number;
+    id: string;
 
     type: SmsServiceType;
 
diff --git a/src/payments/directbilling.ts b/src/payments/directbilling.ts
index abe42fc..0f15faf 100644
--- a/src/payments/directbilling.ts
+++ b/src/payments/directbilling.ts
@@ -75,7 +75,7 @@ export class DirectBilling {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-usludze
      */
-    async getService(id: number): Promise<DbService | undefined> {
+    async getService(id: string): Promise<DbService | undefined> {
         try {
             const service = (await this.client.get(`/${id}`)).data.data;
 
@@ -90,14 +90,14 @@ export class DirectBilling {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#directbilling-kalkulacja-prowizji
      */
-    async calculateCommission(serviceId: number, amount: number): Promise<DbCalculation | undefined> {
+    async calculateCommission(serviceId: string, amount: number): Promise<DbCalculation | undefined> {
         return (await this.client.get(`/${serviceId}/calculate?amount=${amount}`)).data.data;
     }
 
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-listy-transakcji
      */
-    async getTransactions(serviceId: number): Promise<PartialDbTransaction[]> {
+    async getTransactions(serviceId: string): Promise<PartialDbTransaction[]> {
         const result = [];
 
         let response = await this.client.get(`/${serviceId}/transactions`);
@@ -118,7 +118,7 @@ export class DirectBilling {
         });
     }
 
-    async getTransactionsPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<PartialDbTransaction>> {
+    async getTransactionsPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<PartialDbTransaction>> {
         const query: any = {};
 
         if (page) query.page = `${page}`;
@@ -141,7 +141,7 @@ export class DirectBilling {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-transakcji
      */
-    async getTransaction(serviceId: number, transactionId: string): Promise<DbTransaction | undefined> {
+    async getTransaction(serviceId: string, transactionId: string): Promise<DbTransaction | undefined> {
         const transaction = (await this.client.get(`/${serviceId}/transactions/${transactionId}`)).data.data;
 
         transaction.created_at = new Date(transaction.created_at.replace(' ', 'T'));
@@ -153,7 +153,7 @@ export class DirectBilling {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#directbilling-generowanie-transakcji
      */
-    async createTransaction(serviceId: number, key: string, request: DbTransactionRequest): Promise<DbGenerationResponse | undefined> {
+    async createTransaction(serviceId: string, key: string, request: DbTransactionRequest): Promise<DbGenerationResponse | undefined> {
         request.signature = this.generateSignature(key, request);
 
         return (await this.client.post(`/${serviceId}/transactions`, request)).data;
diff --git a/src/payments/sms.ts b/src/payments/sms.ts
index 19f25e1..3ee7551 100644
--- a/src/payments/sms.ts
+++ b/src/payments/sms.ts
@@ -70,7 +70,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-usludze
      */
-    async getService(id: number): Promise<SmsService | undefined> {
+    async getService(id: string): Promise<SmsService | undefined> {
         const service = (await this.client.get(`/${id}`)).data.data;
 
         service.created_at = new Date(service.created_at.replace(' ', 'T'));
@@ -81,7 +81,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-listy-transakcji
      */
-    async getTransactions(serviceId: number): Promise<SmsTransaction[]> {
+    async getTransactions(serviceId: string): Promise<SmsTransaction[]> {
         const result = [];
 
         let response = await this.client.get(`/${serviceId}/transactions`);
@@ -101,7 +101,7 @@ export class Sms {
         });
     }
 
-    async getTransactionsPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsTransaction>> {
+    async getTransactionsPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsTransaction>> {
         const query: any = {};
 
         if (page) query.page = `${page}`;
@@ -123,7 +123,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-transakcji
      */
-    async getTransaction(serviceId: number, transactionId: number): Promise<SmsTransaction | undefined> {
+    async getTransaction(serviceId: string, transactionId: number): Promise<SmsTransaction | undefined> {
         const transaction = (await this.client.get(`/${serviceId}/transactions/${transactionId}`)).data.data;
 
         transaction.send_at = new Date(transaction.send_at.replace(' ', 'T'));
@@ -134,7 +134,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-dostepnych-numerow-dla-uslugi
      */
-    async getServiceNumbers(serviceId: number): Promise<SmsNumber[]> {
+    async getServiceNumbers(serviceId: string): Promise<SmsNumber[]> {
         const result = [];
 
         let response = await this.client.get(`/${serviceId}/numbers`);
@@ -150,7 +150,7 @@ export class Sms {
         return result;
     }
 
-    async getServiceNumbersPaginated(serviceId: number, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsNumber>> {
+    async getServiceNumbersPaginated(serviceId: string, page?: number, pageSize?: number): Promise<PaginatedResponse<SmsNumber>> {
         const query: any = {};
 
         if (page) query.page = `${page}`;
@@ -164,7 +164,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-informacji-o-pojedynczym-numerze-uslugi
      */
-    async getServiceNumber(serviceId: number, number: number): Promise<SmsNumber> {
+    async getServiceNumber(serviceId: string, number: number): Promise<SmsNumber> {
         return (await this.client.get(`/${serviceId}/numbers/${number}`)).data.data;
     }
 
@@ -208,7 +208,7 @@ export class Sms {
     /*
         https://docs.simpay.pl/pl/typescript/?typescript#sms-weryfikacja-poprawnosci-kodu
      */
-    async verifySmsCode(serviceId: number, code: string, number?: number): Promise<VerificationResponse | undefined> {
+    async verifySmsCode(serviceId: string, code: string, number?: number): Promise<VerificationResponse | undefined> {
         const response = (await this.client.post(`/${serviceId}`, { code, number })).data.data;
 
         if( response.used_at ) {
diff --git a/src/tests/directbilling.ts b/src/tests/directbilling.ts
index 84368bb..c66f264 100644
--- a/src/tests/directbilling.ts
+++ b/src/tests/directbilling.ts
@@ -9,29 +9,29 @@ const run = async () => {
     console.log( await db.getServicesPaginated(1, 100) );
 
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-usludze
-    console.log( await db.getService(158) );
+    console.log( await db.getService('19f3b33c') );
 
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-kalkulacja-prowizji
-    console.log( await db.calculateCommission(158, 10.00) );
+    console.log( await db.calculateCommission('19f3b33c', 10.00) );
 
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-listy-transakcji
-    const transactionsList = await db.getTransactions(158);
+    const transactionsList = await db.getTransactions('19f3b33c');
 
     console.log( transactionsList );
 
-    console.log( await db.getTransactionsPaginated(158, 1, 100) );
+    console.log( await db.getTransactionsPaginated('19f3b33c', 1, 100) );
 
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-pobieranie-informacji-o-transakcji
-    console.log( await db.getTransaction(158, transactionsList?.[ 0 ].id) );
+    console.log( await db.getTransaction('19f3b33c', transactionsList?.[ 0 ].id) );
 
     // https://docs.simpay.pl/pl/typescript/?typescript#directbilling-generowanie-transakcji
-    console.log( await db.createTransaction(158, 'key', {
+    console.log( await db.createTransaction('19f3b33c', 'key', {
         amount: 10.00,
         amountType: AmountType.GROSS,
         control: 'test'
     }));
 
-    console.log( await db.checkNotification('key', {}));
+    console.log( db.checkNotification('key', {}));
 };
 
 // eslint-disable-next-line @typescript-eslint/no-empty-function
diff --git a/src/tests/sms.ts b/src/tests/sms.ts
index b6b92ed..6bb1075 100644
--- a/src/tests/sms.ts
+++ b/src/tests/sms.ts
@@ -1,4 +1,4 @@
-import { Sms } from "../payments/sms";
+import { Sms } from '../payments/sms';
 
 const run = async () => {
     const sms = new Sms('0b4dca15', '3eea38f407073ff0abff956b57d71783');
@@ -8,21 +8,21 @@ const run = async () => {
     console.log( await sms.getServicesPaginated(1, 100));
 
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-usludze
-    console.log( await sms.getService(3549));
+    console.log( await sms.getService('d151e4f9'));
 
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-listy-transakcji
-    console.log( await sms.getTransactions(3549));
-    console.log( await sms.getTransactionsPaginated(3549, 1, 100));
+    console.log( await sms.getTransactions('d151e4f9'));
+    console.log( await sms.getTransactionsPaginated('d151e4f9', 1, 100));
 
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-informacji-o-transakcji
-    console.log( await sms.getTransaction(3549, 2216609));
+    console.log( await sms.getTransaction('d151e4f9', 2216609));
 
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-dostepnych-numerow-dla-uslugi
-    console.log( await sms.getServiceNumbers(3549));
-    console.log( await sms.getServiceNumbersPaginated(3549, 1, 100));
+    console.log( await sms.getServiceNumbers('d151e4f9'));
+    console.log( await sms.getServiceNumbersPaginated('d151e4f9', 1, 100));
 
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-informacji-o-pojedynczym-numerze-uslugi
-    console.log( await sms.getServiceNumber(3549, 7055));
+    console.log( await sms.getServiceNumber('d151e4f9', 7055));
     
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-pobieranie-wszystkich-dostepnych-numerow
     console.log( await sms.getNumbers());
@@ -32,8 +32,8 @@ const run = async () => {
     console.log( await sms.getNumber(7055));
     
     // https://docs.simpay.pl/pl/typescript/?typescript#sms-weryfikacja-poprawnosci-kodu
-    console.log( await sms.verifySmsCode(3549, '81FFC5', 7055));
-    console.log( await sms.verifySmsCode(3549, '81FFC5'));
+    console.log( await sms.verifySmsCode('d151e4f9', '81FFC5', 7055));
+    console.log( await sms.verifySmsCode('d151e4f9', '81FFC5'));
 };
 
 // eslint-disable-next-line @typescript-eslint/no-empty-function