This is a randomly generated unique identifier that is required to authenticate requests to transfer domain names from one registrar to another. A UDAI/EPP/Auth code is generated when a domain name is registered. A registrar can generate a new UDAI/EPP/Auth code at any time if required. Registrars are obliged to promptly make UDAI/EPP/Auth codes available to customers, allowing them to transfer their domain name(s) between registrars.