# PATCH /api/v1/transactions/batch/counterparty

> Batch update counterparty

- **Tag:** transactions
- **Operation ID:** `update_transactions_counterparty_api_v1_transactions_batch_counterparty_patch`

## Description

Set the counterparty name for multiple transactions at once.

## Authentication

Bearer token in `Authorization` header.
Required header: `x-business-id: <business uuid>`.

## Request body

Schema: `TransactionBulkUpdateCounterpartyRequest`

- `transaction_ids` (array · string · required) — Array of transaction UUIDs to update.
- `counterparty` (string · required) — Counterparty / merchant name to set on all selected transactions.
- `remember` (boolean) — When true, persist the rename as a per-business counterparty alias so it applies to future transactions too. Registry-linked transactions keep their registry link (the alias overrides the displayed name), and unlinked transactions get a name-keyed alias for their previous raw counterparty string. When false (default), behaves as a one-off rename of the selected rows.

## Responses

### 200 — Successful Response

Schema: `SuccessEnvelope_TransactionListResponse_`

- `success` (boolean)
- `message` (string)
- `code` (string)
- `data` (TransactionListResponse)

### 400 — Bad Request - Invalid input

### 401 — Unauthorized - Authentication required

### 403 — Forbidden - Insufficient permissions

### 404 — Not Found - Resource does not exist

### 422 — Validation Error

Schema: `HTTPValidationError`

- `detail` (array · ValidationError) → `ValidationError`
  - `loc` (array · string | integer · required)
  - `msg` (string · required)
  - `type` (string · required)
  - `input` (object)
  - `ctx` (object)

## Code samples

### cURL

```bash
curl -X PATCH 'https://api.ondayzero.com/api/v1/transactions/batch/counterparty' \
  -H 'Authorization: Bearer dz_your_token' \
  -H 'x-business-id: YOUR_BUSINESS_ID' \
  -H 'Content-Type: application/json' \
  -d '{
  "transaction_ids": [],
  "counterparty": "string"
}'
```

### JavaScript

```javascript
const response = await fetch('https://api.ondayzero.com/api/v1/transactions/batch/counterparty', {
  method: 'PATCH',
  headers: {
    Authorization: 'Bearer dz_your_token',
    'x-business-id': 'YOUR_BUSINESS_ID',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "transaction_ids": [],
  "counterparty": "string"
}),
});
const data = await response.json();
```

### Python

```python
import httpx

headers = {
    "Authorization": "Bearer dz_your_token",
    "x-business-id": "YOUR_BUSINESS_ID",
}

payload = {
  "transaction_ids": [],
  "counterparty": "string"
}

response = httpx.patch("https://api.ondayzero.com/api/v1/transactions/batch/counterparty", headers=headers, json=payload)
data = response.json()
```

## See also

- HTML version: https://www.ondayzero.com/docs/reference/transactions/update-transactions-counterparty
- OpenAPI slice: https://www.ondayzero.com/docs/reference/transactions/update-transactions-counterparty/openapi.json
- Other endpoints in **transactions**: https://www.ondayzero.com/docs/reference/transactions