---
title: "Assign transactions as payment · Bills · COUNT Partner API"
description: "Settles one or more whole transactions against an approved bill or vendor memo. POST /partners/bills/{uuid}/assign-transaction"
canonical: "https://developers.getcount.com/reference/bills/assign-bill-transaction"
source: "https://developers.getcount.com/reference/bills/assign-bill-transaction"
---
[Bills](https://developers.getcount.com/reference/bills) / Assign transactions as payment

# Assign transactions as payment

POST `/partners/bills/{uuid}/assign-transaction`

Settles one or more whole transactions against an approved bill or vendor memo.

Each transaction settles its full amount, and together they cannot exceed the open balance. A bill takes Expense transactions; a vendor memo takes Income transactions, which records a refund received from the vendor. Each transaction is re-categorized to Accounts Payable. The bill must be approved and in the workspace currency — pay a foreign-currency bill with POST /partners/transactions/{transactionId}/assign-to-bills-invoices instead. Transactions must be in the bill currency and must not be pending, excluded, reviewed, or already linked to another bill or invoice. Undo with POST /{uuid}/unassign-transaction. MCP equivalent for vendor memo refunds: COUNT_record_vendor_memo_refund.

HMAC signature + Bearer access token

[Try this request](https://developers.getcount.com/tools/try-it?method=POST&path=%2Fpartners%2Fbills%2F%7Buuid%7D%2Fassign-transaction&body=%7B%0A++%22transactions%22%3A+%5B%0A++++%22b7c8d9e0-f1a2-3456-bcde-678901234567%22%0A++%5D%0A%7D)

[Transactions API](https://developers.getcount.com/reference/transactions) [Vendors API](https://developers.getcount.com/reference/vendors) [Chart of Accounts API](https://developers.getcount.com/reference/chart-of-accounts)

#### Path parameters

`uuid` uuid required

The bill or vendor memo UUID.

#### Request body

`transactions` array required

Transaction UUIDs from the Transactions API.

#### Responses

`200` Transactions assigned. The response is the updated bill, not wrapped in the standard envelope.

`400` No transactions sent; bill is draft, submitted, or rejected; bill is in a foreign currency; wrong transaction type; transaction is pending, excluded, reviewed, or already linked; or the total exceeds the unpaid amount.

`404` Bill not found, or one or more transactions not found in the bill currency.

`409` The bill changed while the payment was being applied. Refresh and retry.

`401` Missing or invalid HMAC signature, expired timestamp, or invalid Bearer token. [Troubleshoot](https://developers.getcount.com/getting-started/errors#error-401)

`403` The credential does not have access to this workspace or resource. [Troubleshoot](https://developers.getcount.com/getting-started/errors#error-403)

`429` Rate limit exceeded (100 requests per minute per clientId). Retry after the Retry-After header. [Troubleshoot](https://developers.getcount.com/getting-started/errors#error-429)

[Previous POST Apply vendor memos to a bill](https://developers.getcount.com/reference/bills/apply-vendor-memos-to-bill) [Next POST Unassign a transaction payment](https://developers.getcount.com/reference/bills/unassign-bill-transaction)

POST `https://api.getcount.com/partners/bills/{uuid}/assign-transaction`

Request

```javascript
import crypto from 'node:crypto';

const BASE_URL = 'https://api.getcount.com';
const CLIENT_ID = process.env.COUNT_CLIENT_ID;
const CLIENT_SECRET = process.env.COUNT_CLIENT_SECRET;
const ACCESS_TOKEN = process.env.COUNT_ACCESS_TOKEN;

const method = 'POST';
const signingPath = '/bills/3fa85f64-5717-4562-b3fc-2c963f66afa6/assign-transaction';
const timestamp = Math.floor(Date.now() / 1000).toString();
const body = {
  "transactions": [
    "b7c8d9e0-f1a2-3456-bcde-678901234567"
  ]
};
const bodyString = JSON.stringify(body);

const bodyHash = crypto.createHash('sha256').update(bodyString).digest('hex');
const baseString = `${method}:${signingPath}:${timestamp}:${bodyHash}`;
const signature = crypto.createHmac('sha256', CLIENT_SECRET).update(baseString).digest('hex');

const response = await fetch(`${BASE_URL}/partners/bills/3fa85f64-5717-4562-b3fc-2c963f66afa6/assign-transaction`, {
  method,
  headers: {
    'x-client-id': CLIENT_ID,
    'x-timestamp': timestamp,
    'x-signature': signature,
    'Content-Type': 'application/json',
    Authorization: `Bearer ${ACCESS_TOKEN}`,
  },
  body: bodyString,
});

console.log(await response.json());
```

Response · 200

```json
{
  "id": "b2c3d4e5-f6a7-8901-bcde-f23456789012",
  "billNumber": "BILL-1042",
  "billType": "bill",
  "date": "2026-01-15",
  "dueDate": "2026-02-15",
  "currency": "USD",
  "approvalStatus": "approved",
  "status": "paid",
  "total": 250,
  "paidAmount": 250,
  "amountDue": 0,
  "notes": "Office supplies for Q1",
  "purchaseOrderNumber": null,
  "isDeleted": false,
  "vendor": {
    "id": "f1a2b3c4-d5e6-7890-abcd-ef1234567890",
    "name": "Office Depot",
    "email": "ap@officedepot.example"
  },
  "lineItems": [
    {
      "id": "a4b5c6d7-e8f9-0123-abcd-456789012345",
      "description": "Office supplies",
      "quantity": 1,
      "price": 250,
      "total": 250,
      "categoryAccountUuid": "c3d4e5f6-a7b8-9012-cdef-123456789012"
    }
  ],
  "transactions": [],
  "appliedVendorMemos": [],
  "tagUuids": [],
  "createdAt": "2026-01-15T10:30:00.000Z",
  "updatedAt": "2026-01-28T14:22:30.000Z"
}
```