What is EPP?

EPP (Extensible Provisioning Protocol) is the industry-standard protocol registrars use to communicate with a registry — creating, transferring, renewing and updating domain registrations programmatically.

It is the machinery behind an ordinary purchase. When a registrar's checkout completes, it opens an authenticated session with the registry, sends a command to create the name, and gets back either a confirmation or a reason it failed. The whole exchange takes milliseconds, which is why a domain appears to be yours the moment you pay.

How it works

EPP is XML over a persistent, mutually authenticated TLS connection. Every registrar holds credentials and a certificate, and connects from IP addresses the registry has allowlisted — so the protocol establishes not just what is being asked, but who is asking.

It models three objects. Domains are the registrations themselves. Hosts are the nameservers a domain points at. Contacts are the parties attached to a registration. Each object supports the same small set of verbs, which is what keeps the protocol learnable.

The commands that do the work

• check — is this name available? The query behind every search box.
• create — register the name for a term, with its contacts and nameservers.
• info — return the current state of an object the registrar sponsors.
• update — change nameservers, contacts, or the status flags that lock a name against transfer or deletion.
• renew — extend the registration term.
• transfer — move sponsorship to another registrar, using the authorisation code the registrant supplies.
• delete — remove the registration, starting the redemption period during which it can still be restored.

Why it matters when a TLD launches

EPP is extensible by design: a registry can add fields for its own requirements — launch phases, eligibility, DNSSEC key material — without breaking clients that don't understand them. That extensibility is the reason a protocol standardised two decades ago still carries every new namespace.

The practical consequence is distribution. A registrar that already speaks EPP can add a new TLD as configuration rather than as an engineering project, which is how a namespace reaches a global retail channel on the day it opens. Standards-compliant EPP is part of how domains.Best integrates with its 300+ registrar partners.