# reference_required

> Admin: a payout needs a payment reference.

Source: https://tickwire.io/docs/errors/reference_required/

HTTP 400.

**Likely cause:** The reference was empty.

**What to do:** Enter the transfer id of the payment you sent.

**Retry:** No. The same request gets the same answer; change something first.

Listed under [Billing, slots and dedicated IPs](https://tickwire.io/docs/errors/#billing-slots-and-dedicated-ips) in [Errors](https://tickwire.io/docs/errors/). Send the error's `requestId` to support and we can find the request.