API error · HTTP 409

`case_exists`

A case with this external_ref already exists

HTTP status	409 Conflict
`code`	`case_exists`
`title`	A case with this external_ref already exists
Retry?	No (handle)

What it means

Your organisation already has a case with this external_ref. external_ref is unique per case (§5).

What to do

Switch to update mode: use the case_id the body returns, or look the case up with GET /v1/cases?external_ref=… (§12.4).

Example response

Branch on code, never on title or detail. detail varies; quote request_id to support.

HTTP

HTTP/1.1 409 Conflict
Content-Type: application/problem+json

{
  "type": "https://www.underwritinguk.ai/developers/errors/case_exists",
  "title": "A case with this external_ref already exists",
  "status": 409,
  "code": "case_exists",
  "detail": "A case with this external_ref already exists.",
  "request_id": "7b0b1e5c-2f7e-4a52-9a43-5b0d0f0e9d11"
}

All error codes · Error catalogue in the integration guide (§15) · Error handling and retries (§12.4)