---
title: "Return 409 Conflict for duplicate email registration"
description: "Duplicate email registration now returns 409 with AUTH_EMAIL_EXISTS instead of 400 with AUTH_REGISTRATION_FAILED."
date: 2026-04-16
tags: ["TIE Auth"]
---

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# Return 409 Conflict for duplicate email registration

Duplicate email registration now returns `409 Conflict` with a dedicated `AUTH_EMAIL_EXISTS` error code. Previously, all registration failures returned `400 Bad Request` with `AUTH_REGISTRATION_FAILED`, forcing callers to pattern-match on the `details` string to detect duplicates.

Callers can now match on the `code` field directly:

```json
{
  "code": "AUTH_EMAIL_EXISTS",
  "message": "A user with this email already exists.",
  "details": null,
  "hint": "Try logging in instead."
}
```

Other registration failures continue to return `400` with `AUTH_REGISTRATION_FAILED`.

For the full error code reference, see [User Tokens — Error Codes](/authentication/overview/).

Source: https://truememory-docs.mvstg.com/changelog/tie-auth/2026-04-16-duplicate-email-409-conflict//index.md