EPP (Extensible Provisioning Protocol)

The protocol registrars use to register and transfer domains, and the source of transfer auth codes.

EPP is the technical protocol used by registrars to communicate with domain registries — registering, renewing, transferring, and deleting domain names. EPP auth codes (also called EPP codes, transfer codes, or authorization codes) are unique strings required to authorize a domain transfer from one registrar to another, preventing unauthorized transfers.