# Voids the vendor bill.

`POST /accounting/vendor-bills/{id}/void`

Group: Accounting › Vendor Bills · Operation ID: `voidVendorBill`

Voids the vendor bill and posts the reversing journal entry that backs it out of the ledger. Voiding is not deleting: the bill, its number and its audit trail stay, and the ledger effect is reversed. A voidReason is required and is stored on the bill for an auditor, so an empty or whitespace-only string is refused. Only an approved, posted, unpaid bill may be voided. Voided and reversed are both terminal, so nothing acts on a bill in either state. A bill whose withheld tax was already remitted gives WITHHOLDING_REMITTED, because it still reads as unpaid when payableAmount is net of the withholding. The posting period must be open. The response is empty.

[Open in the interactive reference](https://docs.api.lensing.ai/?op=voidVendorBill)

## Parameters

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `Api-Version` | header | `"v1"` | yes | The API version this request targets, named by its public identifier. Required on every request; omitting it, or naming a version this company does not have, is answered with 400. This document describes version `v1`. |
| `Idempotency-Key` | header | string | no | An opaque caller-chosen string (1-255 characters) that makes this request safe to retry. Repeating the same key with an identical request body replays the original response instead of re-executing - but only once that original request succeeded; a failed attempt re-executes on retry. Repeating the key with a different body is answered with 422. A key still in flight is answered with 409 - as is a key whose original request was interrupted before it finished, for a few minutes afterwards, until that attempt is presumed dead. A completed response stays replayable for 24 hours. The key is scoped to the caller, not to the action: reusing it for a different action is answered with 409 or 422 rather than treated independently. On read actions this header is ignored. On write actions that cannot offer the guarantee it is answered with `400 IDEMPOTENCY_NOT_SUPPORTED` rather than silently ignored. |
| `id` | path | string | yes | The unique identifier for the vendor bill to void. |

## Request body

Required, `application/json`: voidVendorBillInput.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `voidReason` | string | yes | Why the bill is being voided. Stored on the bill and shown in the audit trail. An empty or whitespace-only string is refused. |

Example:

```json
{
  "voidReason": "Duplicate of VB-295012"
}
```

## Response

`200` Success

## Response headers

- `Idempotency-Replayed` — Present and `true` only when this response replays a previously stored one for the same Idempotency-Key, rather than reflecting a live execution. Absent on a live response - never sent as `false`.

## Errors

| Code | Status |
| --- | --- |
| `NOT_FOUND` | 400 |
| `BILL_NOT_APPROVED` | 400 |
| `BILL_ALREADY_VOIDED` | 400 |
| `BILL_PAID` | 400 |
| `WITHHOLDING_REMITTED` | 400 |
| `BILL_NOT_POSTED` | 400 |
| `POSTING_PERIOD_CLOSED` | 400 |
| `BILL_ALREADY_REVERSED` | 400 |
| `IDEMPOTENCY_KEY_CONFLICT` | 409 |
| `IDEMPOTENCY_PAYLOAD_MISMATCH` | 422 |

## Statuses

- `400` — Invalid request or business failure. Codes: NOT_FOUND, BILL_NOT_APPROVED, BILL_ALREADY_VOIDED, BILL_PAID, WITHHOLDING_REMITTED, BILL_NOT_POSTED, POSTING_PERIOD_CLOSED, BILL_ALREADY_REVERSED
- `401` — Missing or invalid access token
- `403` — Not authorized
- `404` — Not found
- `409` — The Idempotency-Key is still being processed by another request.
- `422` — The Idempotency-Key was already used with a different request payload.
- `429` — Too many requests
- `500` — Internal server error