# Unmatch Bank Transaction

`POST /banking/bank-transactions/{id}/unmatch`

Group: Banking › Bank Transactions · Operation ID: `unmatchBankTransaction`

Detach the match on a bank transaction, addressed by the :id path segment. Dissolves the whole match, returning every transaction in it to unmatched; the documents are returned to the unmatched pool rather than deleted. Returns an empty response. Every request must carry the Api-Version header.

Detaches the match on one bank transaction, identified by the `id` in the path. The response is empty.

**This unmatches the whole match, not just this transaction.** A match can span several transactions and several documents; unmatching any one of them dissolves the match and returns every transaction in it to unmatched.

**A fund transfer is the exception**, because its legs are matched per bank account and so hold one match each. Unmatching one leg leaves the other matched; call this once per leg.

**A bank or credit card entry created for the match must be voided first.** Such an entry exists only because of the match — typically one a bank rule created — so detaching it would leave an orphan. That is `ENTRY_MUST_BE_VOIDED`. An entry that came from an integration carries an `origin` and is exempt.

The documents themselves are untouched: unmatching returns them to the unmatched pool, it does not delete or reverse them.

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

## 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 | Id of the bank transaction to unmatch (a UUID); bound from the :id path segment. |

## 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 |
| `NOT_MATCHED` | 400 |
| `ENTRY_MUST_BE_VOIDED` | 400 |
| `IDEMPOTENCY_KEY_CONFLICT` | 409 |
| `IDEMPOTENCY_PAYLOAD_MISMATCH` | 422 |

## Statuses

- `400` — Invalid request or business failure. Codes: NOT_FOUND, NOT_MATCHED, ENTRY_MUST_BE_VOIDED
- `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