# POST /api/invoicing/credit-notes

Credit Notes: Creates a new credit note.

**Required permissions**: `Invoicing.CreditNotes`, `Invoicing.CreditNotes.Create`  
**Scope**: merchant

**Operation ID:** `creditNoteCreate`

## Authorization

Requires: Invoicing.CreditNotes, Invoicing.CreditNotes.Create, merchant scope.

Requires API key scope: `admin`

Required permissions:
- `Invoicing.CreditNotes`
- `Invoicing.CreditNotes.Create`

## Parameters

| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| suppressNulls | query | no | boolean | If true, omit properties with null values. |

## Request Body

**Content type:** `application/json`

Schema: [`CreditNoteCreateDto`](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteCreateDto.md)

Properties:
- `reason` (string) required: (nullable, max length 1000)
- `lineItems` (array<[CreditNoteLineItemInputDto](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteLineItemInputDto.md)>): (nullable)
  Fields of each item:
  - `originalLineItemId` (string(uuid)): The invoice line being credited. When set, the tax is derived from that line at its effective  rate and the credit cannot exceed the line's net plus tax. Leave null for a free-form credit. (nullable)
  - `description` (string) required: (nullable, max length 500)
  - `quantity` (number(double)): (greater than 0)
  - `unitPrice` (number(double)): Price per unit credited. May carry more than two decimals; the line's net is rounded to the cent.
  - `taxAmount` (number(double)): Tax credited on this line. Honoured, rounded to the cent and floored at zero, only on a free-form  line; on a line that references an original invoice line it is ignored and derived server-side.
  - `lineTotal` (number(double)): Ignored. The persisted line total is always computed server-side and returned on the response.  Kept so existing requests keep deserialising.
- `billerId` (string(uuid)) required
- `billerType` ([InvoicePartyType](https://devportal.demo.winkpg.io/docs/api/models/InvoicePartyType.md)): Identifies the type of entity acting as the biller or recipient on an invoice.
  Values:
  - `GatewayOwner`: Platform-level gateway owner.
  - `Reseller`: Reseller entity.
  - `Merchant`: Merchant entity.
  - `Customer`: End customer.
- `originalInvoiceId` (string(uuid))
- `customerId` (string(uuid)): (nullable)

_Example: Credit part of a billed line_

Records a draft credit note against two of the five license seats an invoice billed. Because the line names the invoice line it credits, the server derives its tax from that line at the rate the invoice charged and caps the credit at the line's net plus tax, so taxAmount and lineTotal are not sent. A credit note is a correction document kept with the invoice: it does not change the invoice's balance and is not sent to the recipient. Money goes back to a payer through POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId and originalLineItemId with the invoice and the line you are crediting, and customerId with the invoice's customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}
```

_Example: Free-form goodwill credit_

Records a draft goodwill credit of 150.00 plus 12.38 of tax that is not tied to any invoice line. A free-form line keeps the tax it is sent, rounded to the cent and never below zero, and the server computes the line total (162.38) itself. The credit note does not change the invoice's balance; return money with POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId with the invoice the credit belongs to, and customerId with its customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}
```

**Content type:** `text/json`

Schema: [`CreditNoteCreateDto`](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteCreateDto.md)

Properties:
- `reason` (string) required: (nullable, max length 1000)
- `lineItems` (array<[CreditNoteLineItemInputDto](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteLineItemInputDto.md)>): (nullable)
  Fields of each item:
  - `originalLineItemId` (string(uuid)): The invoice line being credited. When set, the tax is derived from that line at its effective  rate and the credit cannot exceed the line's net plus tax. Leave null for a free-form credit. (nullable)
  - `description` (string) required: (nullable, max length 500)
  - `quantity` (number(double)): (greater than 0)
  - `unitPrice` (number(double)): Price per unit credited. May carry more than two decimals; the line's net is rounded to the cent.
  - `taxAmount` (number(double)): Tax credited on this line. Honoured, rounded to the cent and floored at zero, only on a free-form  line; on a line that references an original invoice line it is ignored and derived server-side.
  - `lineTotal` (number(double)): Ignored. The persisted line total is always computed server-side and returned on the response.  Kept so existing requests keep deserialising.
- `billerId` (string(uuid)) required
- `billerType` ([InvoicePartyType](https://devportal.demo.winkpg.io/docs/api/models/InvoicePartyType.md)): Identifies the type of entity acting as the biller or recipient on an invoice.
  Values:
  - `GatewayOwner`: Platform-level gateway owner.
  - `Reseller`: Reseller entity.
  - `Merchant`: Merchant entity.
  - `Customer`: End customer.
- `originalInvoiceId` (string(uuid))
- `customerId` (string(uuid)): (nullable)

_Example: Credit part of a billed line_

Records a draft credit note against two of the five license seats an invoice billed. Because the line names the invoice line it credits, the server derives its tax from that line at the rate the invoice charged and caps the credit at the line's net plus tax, so taxAmount and lineTotal are not sent. A credit note is a correction document kept with the invoice: it does not change the invoice's balance and is not sent to the recipient. Money goes back to a payer through POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId and originalLineItemId with the invoice and the line you are crediting, and customerId with the invoice's customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}
```

_Example: Free-form goodwill credit_

Records a draft goodwill credit of 150.00 plus 12.38 of tax that is not tied to any invoice line. A free-form line keeps the tax it is sent, rounded to the cent and never below zero, and the server computes the line total (162.38) itself. The credit note does not change the invoice's balance; return money with POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId with the invoice the credit belongs to, and customerId with its customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}
```

**Content type:** `application/*+json`

Schema: [`CreditNoteCreateDto`](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteCreateDto.md)

Properties:
- `reason` (string) required: (nullable, max length 1000)
- `lineItems` (array<[CreditNoteLineItemInputDto](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteLineItemInputDto.md)>): (nullable)
  Fields of each item:
  - `originalLineItemId` (string(uuid)): The invoice line being credited. When set, the tax is derived from that line at its effective  rate and the credit cannot exceed the line's net plus tax. Leave null for a free-form credit. (nullable)
  - `description` (string) required: (nullable, max length 500)
  - `quantity` (number(double)): (greater than 0)
  - `unitPrice` (number(double)): Price per unit credited. May carry more than two decimals; the line's net is rounded to the cent.
  - `taxAmount` (number(double)): Tax credited on this line. Honoured, rounded to the cent and floored at zero, only on a free-form  line; on a line that references an original invoice line it is ignored and derived server-side.
  - `lineTotal` (number(double)): Ignored. The persisted line total is always computed server-side and returned on the response.  Kept so existing requests keep deserialising.
- `billerId` (string(uuid)) required
- `billerType` ([InvoicePartyType](https://devportal.demo.winkpg.io/docs/api/models/InvoicePartyType.md)): Identifies the type of entity acting as the biller or recipient on an invoice.
  Values:
  - `GatewayOwner`: Platform-level gateway owner.
  - `Reseller`: Reseller entity.
  - `Merchant`: Merchant entity.
  - `Customer`: End customer.
- `originalInvoiceId` (string(uuid))
- `customerId` (string(uuid)): (nullable)

_Example: Credit part of a billed line_

Records a draft credit note against two of the five license seats an invoice billed. Because the line names the invoice line it credits, the server derives its tax from that line at the rate the invoice charged and caps the credit at the line's net plus tax, so taxAmount and lineTotal are not sent. A credit note is a correction document kept with the invoice: it does not change the invoice's balance and is not sent to the recipient. Money goes back to a payer through POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId and originalLineItemId with the invoice and the line you are crediting, and customerId with the invoice's customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}
```

_Example: Free-form goodwill credit_

Records a draft goodwill credit of 150.00 plus 12.38 of tax that is not tied to any invoice line. A free-form line keeps the tax it is sent, rounded to the cent and never below zero, and the server computes the line total (162.38) itself. The credit note does not change the invoice's balance; return money with POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId with the invoice the credit belongs to, and customerId with its customer.

```json
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}
```

## Responses

### 200

OK

**Content type:** `application/json`

Schema: [`CreditNoteDto`](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteDto.md)

Properties:
- `id` (string(uuid))
- `creationTime` (string(date-time)): The date and time when this entity was created.
- `creatorId` (string(uuid)): The ID of the user who created this entity. (nullable)
- `lastModificationTime` (string(date-time)): The date and time when this entity was last modified. (nullable)
- `lastModifierId` (string(uuid)): The ID of the user who last modified this entity. (nullable)
- `billerId` (string(uuid))
- `billerType` ([InvoicePartyType](https://devportal.demo.winkpg.io/docs/api/models/InvoicePartyType.md)): Identifies the type of entity acting as the biller or recipient on an invoice.
  Values:
  - `GatewayOwner`: Platform-level gateway owner.
  - `Reseller`: Reseller entity.
  - `Merchant`: Merchant entity.
  - `Customer`: End customer.
- `creditNoteNumber` (string): (nullable)
- `originalInvoiceId` (string(uuid))
- `customerId` (string(uuid)): (nullable)
- `reason` (string): (nullable)
- `lineItems` (array<[CreditNoteLineItemDto](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteLineItemDto.md)>): (nullable)
  Fields of each item:
  - `id` (string(uuid))
  - `originalLineItemId` (string(uuid)): (nullable)
  - `description` (string): (nullable)
  - `quantity` (number(double))
  - `unitPrice` (number(double))
  - `taxAmount` (number(double)): Tax credited on this line, as computed server-side.
  - `lineTotal` (number(double)): Net plus tax credited on this line, as computed server-side.
- `total` (number(double)): (nullable)
- `status` ([CreditNoteStatus](https://devportal.demo.winkpg.io/docs/api/models/CreditNoteStatus.md)): Lifecycle status of a credit note.
  Values:
  - `Draft`: Created, not yet issued.
  - `Issued`: Issued and available to apply.
  - `Applied`: Applied to the original invoice.
  - `Voided`: Voided and no longer valid.
- `issuedAt` (string(date-time)): (nullable)
- `appliedAt` (string(date-time)): (nullable)
- `concurrencyStamp` (string): (nullable)

### 403

Forbidden

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

### 401

Unauthorized

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

### 400

Bad Request

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

_Example: Request failed validation_

One or more fields were rejected before any rule ran. error.code is null on the envelope and the causes are in validationErrors, one entry per failure. An entry carries code when the validator declared a publishable one, and memberPaths when the full path says more than members does (an element inside a collection, for example). Both keys are omitted when they would add nothing.

```json
{
  "error": {
    "code": "null",
    "message": "Your request is not valid!",
    "details": "The following errors were detected during validation.",
    "data": {
      "correlationId": "0123456789abcdef0123456789abcdef"
    },
    "validationErrors": [
      {
        "message": "'Amount' must be greater than 0.",
        "members": [
          "amount"
        ]
      },
      {
        "message": "The card has expired.",
        "members": [
          "expirationDate"
        ],
        "code": "CardData:CardExpired"
      },
      {
        "message": "'Value' must not be empty.",
        "members": [
          "value"
        ],
        "memberPaths": [
          "customFields[2].value"
        ]
      }
    ]
  }
}
```

### 404

Not Found

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

_Example: Resource not found_

The id in the path names no record the caller can see. Most resources answer with a null error.code and a message naming the resource type and the id; a resource that publishes a not-found code in the catalog above carries it in error.code instead, so check for one before matching on the message.

```json
{
  "error": {
    "code": "null",
    "message": "There is no entity Transaction with id = 7d1f3a52-0c4e-4b8a-9e21-5a6b7c8d9e00!",
    "details": "null",
    "data": {
      "correlationId": "0123456789abcdef0123456789abcdef"
    },
    "validationErrors": "null"
  }
}
```

### 501

Not Implemented

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

### 500

Internal Server Error

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

### default

The request failed. The body carries the standard error envelope: a machine-readable `error.code`, a human-readable `error.message`, and `error.validationErrors` when the failure was a validation rejection. The [error reference](https://devportal.demo.winkpg.io/docs/errors.md) lists the values `error.code` can take.

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

_Example: Business rule refused the request_

The request was understood and rejected by a platform rule. This is the shape that carries a code from the catalog above, so branch on error.code rather than on the message text. The HTTP status is the one listed against the code.

```json
{
  "error": {
    "code": "Transactions:OperationNotAllowed",
    "message": "The operation 'Void' is not allowed on a Sale transaction with result 'Approved' and settlement state 'Settled'.",
    "details": "null",
    "data": {
      "correlationId": "0123456789abcdef0123456789abcdef"
    },
    "validationErrors": "null"
  }
}
```

### 429

The request was refused because a rate limit was exceeded, or because something a later retry can clear stopped it. A rate limit refusal carries an `application/problem+json` body: wait at least the interval `Retry-After` names before retrying, then back off. Limits are tuned per deployment, so read the allowance from the response headers rather than assuming a fixed ceiling. Any other refusal carries the standard error envelope as `application/json`, and its `error.code` names the cause.

**Content type:** `application/problem+json`

Schema: [`RateLimitProblemDetails`](https://devportal.demo.winkpg.io/docs/api/models/RateLimitProblemDetails.md)

Properties:
- `type` (string) required: The problem type identifier. Always the same value: the failure is the status code itself,  so there is no sub-type for a caller to branch on. (nullable)
- `title` (string) required: A short, human-readable summary of the problem type. (nullable)
- `status` (integer(int32)) required: The HTTP status code, repeated in the body as the problem-details format defines.
- `detail` (string) required: A human-readable explanation of this occurrence of the problem. (nullable)
- `retryAfterSeconds` (integer(int32)) required: How long to wait before retrying, in whole seconds, carrying the same figure as the  `Retry-After` header. Always at least one: a value of zero would invite an immediate  retry that is certain to be rejected again.

**Content type:** `application/json`

Schema: [`RemoteServiceErrorResponse`](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorResponse.md)

Properties:
- `error` ([RemoteServiceErrorInfo](https://devportal.demo.winkpg.io/docs/api/models/RemoteServiceErrorInfo.md))

## Example request

Every block below sends the same request. Replace {{BASE_URL}} with the address of the API you are calling and {{API_KEY}} with your own key.

The request body is a CreditNoteCreateDto. See the Request body section below for its fields.

These blocks send the Credit part of a billed line example. The other examples follow under Other request examples.

Records a draft credit note against two of the five license seats an invoice billed. Because the line names the invoice line it credits, the server derives its tax from that line at the rate the invoice charged and caps the credit at the line's net plus tax, so taxAmount and lineTotal are not sent. A credit note is a correction document kept with the invoice: it does not change the invoice's balance and is not sent to the recipient. Money goes back to a payer through POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId and originalLineItemId with the invoice and the line you are crediting, and customerId with the invoice's customer.

### cURL

```bash
curl -X POST "{{BASE_URL}}/api/invoicing/credit-notes" \
  -H "api-key: {{API_KEY}}" \
  -H "Content-Type: application/json" \
  -d '{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}'
```

### PowerShell

```powershell
$headers = @{
    'api-key' = '{{API_KEY}}'
}

$body = @'
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}
'@

$response = Invoke-RestMethod -Method POST -Uri '{{BASE_URL}}/api/invoicing/credit-notes' `
    -Headers $headers -ContentType 'application/json' -Body $body
```

### TypeScript (SDK)

```bash
npm install @winkpg/winkpg-api
```

```typescript
import { Configuration, InvoicingApi } from '@winkpg/winkpg-api';

const api = new InvoicingApi(new Configuration({
  basePath: '{{BASE_URL}}',
  apiKey: '{{API_KEY}}',
}));

const { data } = await api.creditNoteCreate({
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
});
```

### TypeScript (raw HTTP)

```typescript
const response = await fetch('{{BASE_URL}}/api/invoicing/credit-notes', {
  method: 'POST',
  headers: {
    "api-key": "{{API_KEY}}",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "billerId": "00000000-0000-0000-0000-000000000001",
    "billerType": "Merchant",
    "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
    "customerId": "00000000-0000-0000-0000-000000000201",
    "reason": "Two license seats were not activated.",
    "lineItems": [
      {
        "originalLineItemId": "00000000-0000-0000-0000-000000000602",
        "description": "Logo usage license, one seat each",
        "quantity": 2,
        "unitPrice": 120
      }
    ]
  }),
});

const data = await response.json();
```

### C# (SDK)

```bash
dotnet add package WinkPg.Api.Client
```

```csharp
using WinkPg.Api.Client.Api;
using WinkPg.Api.Client.Client;
using System.Text.Json;

var config = new Configuration { BasePath = "{{BASE_URL}}" };
config.AddApiKey("api-key", "{{API_KEY}}");

var api = new InvoicingApi(config);
var body = JsonSerializer.Deserialize<CreditNoteCreateDto>("""
    {
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Two license seats were not activated.",
      "lineItems": [
        {
          "originalLineItemId": "00000000-0000-0000-0000-000000000602",
          "description": "Logo usage license, one seat each",
          "quantity": 2,
          "unitPrice": 120
        }
      ]
    }
    """);

var result = await api.CreditNoteCreateAsync(body);
```

### C# (raw HTTP)

```csharp
using System.Text;

using var http = new HttpClient { BaseAddress = new Uri("{{BASE_URL}}") };

var request = new HttpRequestMessage(new HttpMethod("POST"), "/api/invoicing/credit-notes");
request.Headers.Add("api-key", "{{API_KEY}}");

request.Content = new StringContent("""
    {
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Two license seats were not activated.",
      "lineItems": [
        {
          "originalLineItemId": "00000000-0000-0000-0000-000000000602",
          "description": "Logo usage license, one seat each",
          "quantity": 2,
          "unitPrice": 120
        }
      ]
    }
    """, Encoding.UTF8, "application/json");

var response = await http.SendAsync(request);
response.EnsureSuccessStatusCode();
var json = await response.Content.ReadAsStringAsync();
```

### Python (SDK)

```bash
pip install winkpg-api
```

```python
import winkpg_api

configuration = winkpg_api.Configuration(host="{{BASE_URL}}")
configuration.api_key["ApiKey"] = "{{API_KEY}}"

with winkpg_api.ApiClient(configuration) as client:
    api = winkpg_api.InvoicingApi(client)
    body = winkpg_api.CreditNoteCreateDto.from_dict({
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Two license seats were not activated.",
      "lineItems": [
        {
          "originalLineItemId": "00000000-0000-0000-0000-000000000602",
          "description": "Logo usage license, one seat each",
          "quantity": 2,
          "unitPrice": 120
        }
      ]
    })
    result = api.credit_note_create(body)
```

### Python (raw HTTP)

```bash
pip install requests
```

```python
import requests

headers = {
    "api-key": "{{API_KEY}}",
    "Content-Type": "application/json",
}

body = {
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Two license seats were not activated.",
  "lineItems": [
    {
      "originalLineItemId": "00000000-0000-0000-0000-000000000602",
      "description": "Logo usage license, one seat each",
      "quantity": 2,
      "unitPrice": 120
    }
  ]
}

response = requests.request(
    "POST",
    "{{BASE_URL}}/api/invoicing/credit-notes",
    headers=headers,
    json=body,
)
response.raise_for_status()
data = response.json()
```

## Other request examples

Each example below is one request, shown in every language with the same placeholders.

### Free-form goodwill credit

Records a draft goodwill credit of 150.00 plus 12.38 of tax that is not tied to any invoice line. A free-form line keeps the tax it is sent, rounded to the cent and never below zero, and the server computes the line total (162.38) itself. The credit note does not change the invoice's balance; return money with POST /api/invoicing/invoices/{id}/refund. Replace billerId with your merchant's id, originalInvoiceId with the invoice the credit belongs to, and customerId with its customer.

#### cURL

```bash
curl -X POST "{{BASE_URL}}/api/invoicing/credit-notes" \
  -H "api-key: {{API_KEY}}" \
  -H "Content-Type: application/json" \
  -d '{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}'
```

#### PowerShell

```powershell
$headers = @{
    'api-key' = '{{API_KEY}}'
}

$body = @'
{
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}
'@

$response = Invoke-RestMethod -Method POST -Uri '{{BASE_URL}}/api/invoicing/credit-notes' `
    -Headers $headers -ContentType 'application/json' -Body $body
```

#### TypeScript (SDK)

```bash
npm install @winkpg/winkpg-api
```

```typescript
import { Configuration, InvoicingApi } from '@winkpg/winkpg-api';

const api = new InvoicingApi(new Configuration({
  basePath: '{{BASE_URL}}',
  apiKey: '{{API_KEY}}',
}));

const { data } = await api.creditNoteCreate({
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
});
```

#### TypeScript (raw HTTP)

```typescript
const response = await fetch('{{BASE_URL}}/api/invoicing/credit-notes', {
  method: 'POST',
  headers: {
    "api-key": "{{API_KEY}}",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "billerId": "00000000-0000-0000-0000-000000000001",
    "billerType": "Merchant",
    "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
    "customerId": "00000000-0000-0000-0000-000000000201",
    "reason": "Goodwill credit for a late delivery.",
    "lineItems": [
      {
        "description": "Goodwill credit for a late delivery",
        "quantity": 1,
        "unitPrice": 150,
        "taxAmount": 12.38
      }
    ]
  }),
});

const data = await response.json();
```

#### C# (SDK)

```bash
dotnet add package WinkPg.Api.Client
```

```csharp
using WinkPg.Api.Client.Api;
using WinkPg.Api.Client.Client;
using System.Text.Json;

var config = new Configuration { BasePath = "{{BASE_URL}}" };
config.AddApiKey("api-key", "{{API_KEY}}");

var api = new InvoicingApi(config);
var body = JsonSerializer.Deserialize<CreditNoteCreateDto>("""
    {
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Goodwill credit for a late delivery.",
      "lineItems": [
        {
          "description": "Goodwill credit for a late delivery",
          "quantity": 1,
          "unitPrice": 150,
          "taxAmount": 12.38
        }
      ]
    }
    """);

var result = await api.CreditNoteCreateAsync(body);
```

#### C# (raw HTTP)

```csharp
using System.Text;

using var http = new HttpClient { BaseAddress = new Uri("{{BASE_URL}}") };

var request = new HttpRequestMessage(new HttpMethod("POST"), "/api/invoicing/credit-notes");
request.Headers.Add("api-key", "{{API_KEY}}");

request.Content = new StringContent("""
    {
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Goodwill credit for a late delivery.",
      "lineItems": [
        {
          "description": "Goodwill credit for a late delivery",
          "quantity": 1,
          "unitPrice": 150,
          "taxAmount": 12.38
        }
      ]
    }
    """, Encoding.UTF8, "application/json");

var response = await http.SendAsync(request);
response.EnsureSuccessStatusCode();
var json = await response.Content.ReadAsStringAsync();
```

#### Python (SDK)

```bash
pip install winkpg-api
```

```python
import winkpg_api

configuration = winkpg_api.Configuration(host="{{BASE_URL}}")
configuration.api_key["ApiKey"] = "{{API_KEY}}"

with winkpg_api.ApiClient(configuration) as client:
    api = winkpg_api.InvoicingApi(client)
    body = winkpg_api.CreditNoteCreateDto.from_dict({
      "billerId": "00000000-0000-0000-0000-000000000001",
      "billerType": "Merchant",
      "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
      "customerId": "00000000-0000-0000-0000-000000000201",
      "reason": "Goodwill credit for a late delivery.",
      "lineItems": [
        {
          "description": "Goodwill credit for a late delivery",
          "quantity": 1,
          "unitPrice": 150,
          "taxAmount": 12.38
        }
      ]
    })
    result = api.credit_note_create(body)
```

#### Python (raw HTTP)

```bash
pip install requests
```

```python
import requests

headers = {
    "api-key": "{{API_KEY}}",
    "Content-Type": "application/json",
}

body = {
  "billerId": "00000000-0000-0000-0000-000000000001",
  "billerType": "Merchant",
  "originalInvoiceId": "00000000-0000-0000-0000-000000000601",
  "customerId": "00000000-0000-0000-0000-000000000201",
  "reason": "Goodwill credit for a late delivery.",
  "lineItems": [
    {
      "description": "Goodwill credit for a late delivery",
      "quantity": 1,
      "unitPrice": 150,
      "taxAmount": 12.38
    }
  ]
}

response = requests.request(
    "POST",
    "{{BASE_URL}}/api/invoicing/credit-notes",
    headers=headers,
    json=body,
)
response.raise_for_status()
data = response.json()
```

## See also

- [All documentation](https://devportal.demo.winkpg.io/llms.txt): the machine-readable index of every public page on this site.