Overview
A domain registrar is a company or organisation that is accredited to register domain names on behalf of individuals and businesses. When someone wants to claim a domain name — for example, mybusiness.co — they do so through a registrar. The registrar handles the technical process of creating the domain record in the global Domain Name System (DNS) and maintaining it for as long as the registration is active.
Registrars act as the bridge between the end customer (the registrant) and the domain registry that operates the top-level domain (TLD). Without registrars, customers would have no practical way to register domain names.
| In short: a registry sets the rules and runs the infrastructure. A registrar sells domain names to the public under those rules. The registrant is the customer who owns the domain. |
Registry vs Registrar — What Is the Difference?
These two terms are often confused. Here is a clear breakdown of how they differ:
| Registry | Registrar | |
| What it does | Operates the authoritative database for a TLD (e.g. .CO, .COM). Sets rules, manages DNS infrastructure. | Sells domain registrations to the public. Communicates with the registry on behalf of customers. |
| Who it serves | Registrars (its direct customers) | Registrants — individuals and businesses who want to own a domain name. |
| Customer-facing? | No — registries do not typically interact with end customers. | Yes — registrars provide shopping carts, control panels, and customer support. |
| .CO example | CentralNic / .CO Registry (registry.co) | Any accredited .CO Registrar (e.g. GoDaddy, Namecheap, and others) |
| Accreditation | Granted authority by ICANN or national authority. | Must be accredited by the relevant registry and sign a Registrar-Registry Agreement (RRA). |
What Does a Registrar Actually Do?
A registrar's core responsibilities span the full lifecycle of a domain name:
1. Domain Registration
When a customer wants to register a domain, the registrar checks availability with the registry, creates the domain record in the registry's Shared Registry System (SRS), and publishes the domain's DNS delegation. In the .CO Registry, this is done via the Extensible Provisioning Protocol (EPP) — the industry-standard protocol for registry-registrar communication.
2. Domain Renewal
Registrars manage domain renewals on behalf of their customers — either automatically (Auto-Renew) or manually at the customer's request. In the .CO Registry, domains can be registered for 1 to 5 years and renewed for any whole number of additional years, subject to the maximum 5-year registration window.
3. Domain Transfers
If a customer wishes to move their domain to a different registrar (the gaining registrar), the current registrar (the losing registrar) is required to facilitate the transfer. This includes providing the customer with the authorisation code (authInfo code) needed to initiate the transfer. The gaining registrar then submits the transfer request to the registry.
4. DNS Management
Registrars update the nameserver (host object) records associated with a domain, directing traffic to the customer's website, email servers, and other services. For .CO domains, a domain can have between 0 and 13 nameservers.
5. Contact Management
Every domain registration requires contact information — Registrant, Administrative, Technical, and Billing contacts. Registrars collect and maintain this data and submit it to the registry in the format required by the relevant standards (RFC 5733 for EPP contact objects).
6. WHOIS and RDAP Data
Registrars are responsible for ensuring the accuracy of domain registration data. This information is published via the WHOIS and RDAP services, which allow anyone to look up who is responsible for a domain name.
7. Customer Support and Domain Security
Registrars typically apply domain lock statuses (such as clientTransferProhibited and clientDeleteProhibited) to protect domains from unauthorised transfers or deletions. They also handle customer support for domain-related issues, from login problems to expired registrations.
How Registrars Connect to the .CO Registry
The .CO Registry provides three technical interfaces that accredited Registrars use to manage domain names:
- Registrar Console: A web-based dashboard at https://registrar-console.registry.co/ for managing domains, transfers, contacts, billing, and account settings. Suitable for manual operations and account administration.
- EPP Server: The primary programmatic interface. Registrars connect via TLS-encrypted TCP to epp.registry.co on port 700 and submit XML commands to create, update, renew, transfer, and delete domain objects. This interface is used for automation and high-volume operations.
- FTP Server: An FTPS server at ftp-registrar.registry.co (port 21) that provides downloadable data files — including domain drop lists, pricing information, and billable transaction reports.
Access to the EPP and FTP servers is restricted to IP addresses that the Registrar has explicitly whitelisted in their account settings.
How Does a Company Become a .CO Registrar?
To become an accredited .CO Registrar, a company must:
- Contact the .CO Registry at support@registry.co to request accreditation.
- Review and sign the .CO Registrar-Registry Agreement (RRA) — the legal contract governing the Registrar's access to and use of the Registry system.
- Receive a Registrar ID and credentials from the Registry.
- Configure their technical systems (EPP client, Registrar Console access, IP whitelist).
- Fund their prepaid account balance to cover domain registration fees.
- Begin accepting and processing domain registrations.
No funds deposit is required before signing the RRA, and no formal Operational Testing and Evaluation (OT&E) certification is required before accessing the production environment. However, Registrars are strongly encouraged to test their EPP client in the OT&E environment (epp.ote.registry.co, port 700) before going live.
Registrar Obligations
Once accredited, a .CO Registrar takes on a number of obligations:
- Maintain accurate registrant data: Registrars must collect and submit accurate contact information for each domain registration.
- Provide authInfo codes on request: Registrars are required to give registrants their domain's authorisation code when requested — this enables the registrant to transfer to another Registrar.
- Maintain sufficient account balance: Registrars must keep their prepaid balance topped up to cover their expected transaction volumes. The Registry will block domain operations if the balance is exhausted.
- Comply with the Fair Use Policy: Registrars must ensure their EPP and WHOIS usage complies with protocol standards and the Registry's rate-limit policies.
- Keep contact details current: Registrars must specify a valid Operations email address to receive maintenance notifications and system alerts.
Registrar vs Reseller — What Is the Difference?
A registrar is directly accredited by the registry and holds the technical and legal relationship with the registry. A reseller is a company or individual that sells domain names through an accredited registrar but has no direct relationship with the registry itself.
| Registrar | Reseller | |
| Registry relationship | Direct — holds the RRA with the registry | None — works through an accredited registrar |
| EPP access | Yes — connects directly to the registry EPP server | No — relies on the registrar's systems |
| Registry liability | Directly responsible to the registry for compliance | Reseller agreement is with the registrar only |
| Branded experience | Can build a fully branded registration platform | Typically white-labels the registrar's platform |
The .CO Registry does not directly support a reseller layer — reseller arrangements are commercial agreements between an accredited Registrar and their downstream partners.