---
title: "Precondition required"
description: "This operation requires the If-Match header."
lang: en
url: https://developers.bodo-app.com/en/problems/PRECONDITION_REQUIRED/
apiVersion: 2026-11-01
---

# Precondition required

This operation requires the If-Match header.

**Status 428** · `PRECONDITION_REQUIRED`

## Typical cause

The operation requires `If-Match` so that a concurrent change is not overwritten, and the header is missing.

## Way out

Read the record and send its ETag as `If-Match`.

## Example response

**Example response**

```http
PATCH /v1/contacts/con_4Nf7…

HTTP/1.1 428 Precondition Required
Content-Type: application/problem+json
Content-Language: en

{
  "type": "https://developers.bodo-app.com/problems/PRECONDITION_REQUIRED",
  "title": "Precondition required",
  "status": 428,
  "instance": "/v1/contacts/con_4Nf7…",
  "code": "PRECONDITION_REQUIRED",
  "requestId": "req_01JBD8Y3K5M7Q2W9X4Z6T1V0NP"
}
```

## Related

- [412 PRECONDITION_FAILED](/en/problems/PRECONDITION_FAILED/) · Precondition failed

Read on: [Idempotency & revisions](/en/guides/idempotency/)