What It Is
An auth code, sometimes called an EPP code or transfer key, is a unique code tied to your domain. You get it from your current registrar and give it to the new one when you transfer. It works like a release code for moving a phone number to a new carrier: without it, the move cannot happen. EPP is the name of the system registrars use to talk to the registry that runs each domain ending.
Why It Matters for Your Business
The auth code protects your domain from being stolen. If someone gains access to your new registrar account but not your old one, they still cannot move the domain away. For a business, this means your website address and email cannot be quietly hijacked by a simple form submission.
Good to Know
Treat the auth code like a password. Share it only with the registrar you are moving to, never by public message. If a transfer fails, the code may have expired or been mistyped, so ask your registrar for a fresh one. Codes can expire after a short time.