# E04058 — ContactMatchAmbiguous

This entry's identifiers belong to more than one contact.

- **HTTP status**: `409`
- **Type**: `conflict_error`
- **Name**: `ContactMatchAmbiguous`

## What to do

The entry matched more than one existing contact. The error message names each matched contact and the identifier that matched it. Decide which contact this entry means, then resend it carrying only that contact's identifiers, or update the contacts directly.

Operations that resolve this:

- [List contacts](/docs/api/reference/list-contacts)
- [Update a contact](/docs/api/reference/update-contact)

## Related

- [Idempotency](/docs/api/idempotency): safe retries and key reuse rules
- [E04xxx — Email sending & delivery](/docs/api/errors/E04xxx): every code in this range
- [Errors](/docs/api/errors): the full wire contract, status mapping, and error catalog
- [Error handling](/docs/guides/errors): branching on `type` and `code`, validation details, and `vendor_code`