What is an authorization (EPP) code?

An authorization code (EPP code) is a code generated by a domain registrar when a domain transfer request for a top level domain (.com, .net., .biz for example) is received. This authorization code is given to the customer, who then provides the code to the new registrar.

The EPP code specifies to the new registrar that the domain name is authorized to be transferred from the old registrar.