WHOIS and RDAP: where this information comes from
Every registered domain has a record at its registry — Nominet for .uk, Verisign for .com and .net, Public Interest Registry for .org, and hundreds of others. Traditionally you read that record with the WHOIS protocol on port 43, which returns free-form text and cannot be used from a web browser. RDAP (Registration Data Access Protocol) has been mandatory for every generic top-level domain since 2019 and officially replaced WHOIS for them in January 2025: structured JSON, served over HTTPS, with standard fields for dates, status codes and contacts.
This tool is an RDAP client. Your browser first reads IANA’s official bootstrap file (data.iana.org/rdap/dns.json), which says which server is authoritative for each extension, then asks that registry directly — for example rdap.nominet.uk for bbc.co.uk. For .com and .net the registry points to the registrar’s own RDAP server, which the tool also queries and merges, because the registrar holds the contact data. A handful of registries don’t allow browser requests; for those only, the query passes through a tiny relay of ours that talks exclusively to official RDAP servers and keeps nothing. The raw JSON from each source is available under Source & raw RDAP data.
Reading the results: dates, expiry and status codes
Registered is when the current registration began — a domain that lapsed and was re-registered gets a new date, so this is not always the brand’s age. Last updated changes with any edit, including nameserver or contact changes. Expires is paid-up-until; the countdown turns amber at 90 days and red at 30.
What happens after expiry depends on the extension. Most generic domains enter an auto-renew grace period of up to 45 days, then a 30-day redemption period in which only the previous owner can restore them for a fee, then five days of pending delete before anyone can register them. A .uk domain keeps working for about 30 days after expiry, is then suspended, and is cancelled roughly 90 days after expiry if nobody renews it.
| Status | Meaning |
|---|---|
clientTransferProhibited | Registrar lock — good; stops unauthorised transfers |
serverTransferProhibited | Registry lock or the 60-day post-transfer freeze |
clientHold / serverHold | Suspended and removed from DNS — the site and email stop working |
redemptionPeriod | Expired and deleted, restorable only by the previous owner |
pendingDelete | About to be released to the public |
autoRenewPeriod | Renewed automatically at expiry; renewal can still be cancelled |
Nominet shows its locks as “server … prohibited”; .uk registrars rarely set client locks, so their absence on a .uk name is normal.
Who owns a domain? Privacy, redaction and contacting the owner
Since GDPR took effect in 2018, registries and registrars redact personal data. For most domains you will see the registrant’s country and sometimes an organisation name, with name, address, email and phone marked redacted for privacy. Nominet publishes the registrant’s name only for some organisations and never shows personal details of individuals. That is policy, not a fault in the lookup.
To reach an owner, use the registrar’s contact form (the tool links it when the registrar publishes one) or email the address on the website itself. To report phishing, malware or spam, use the abuse contact: registrars accredited by ICANN must investigate reports sent there. For a .uk domain you can also report criminal use to Nominet. If you need the real registrant for a legal claim, registrars disclose it on a valid legal request, and brand owners can use ICANN’s Registration Data Request Service for generic domains.
Is the domain available? What “no registration found” means
When the registry answers “not found”, the tool shows Looks available and cross-checks DNS: if the name doesn’t resolve either, it is almost certainly free to register at any registrar. It is a strong hint rather than a promise — registries also answer “not found” for some reserved words, blocked names and premium domains priced separately, and a name deleted minutes ago may be in a drop queue.
Some extensions don’t run RDAP at all. Many country-code registries, including .eu, .ie, .es, .it and .jp, still offer only port-43 WHOIS, which a browser cannot reach, so the tool says so plainly and links the registry’s own search and IANA’s record for the extension instead of guessing. Every generic extension (.com, .org, .shop, .app…) and .uk, .fr, .nl, .de, .ch, .io and .us are covered.
IP address and AS number lookups
Type an IP address and the tool asks the regional internet registry responsible for it — RIPE NCC for the UK and Europe, ARIN for North America, APNIC, LACNIC or AFRINIC — via IANA’s IPv4 and IPv6 bootstrap files. You get the network name, the allocated range in CIDR form, the organisation, country and, most usefully, the abuse email to report attacks or spam coming from that address. Type AS2856 (BT) or any other AS number to see who operates that network.
IP WHOIS identifies the provider, not the person: a home broadband address belongs to BT, Sky, Virgin Media or whichever ISP assigned it, and only the ISP can link it to a customer. Private addresses such as 192.168.1.1 or carrier-grade NAT space have no WHOIS record at all; to see your own public address, use What is my IP, and to check what a domain’s addresses and mail servers are, use the DNS lookup.
Frequently asked questions
Why is the owner’s name hidden?
Data-protection law (GDPR and the UK GDPR) and ICANN policy require registries and registrars to redact personal details of registrants. Organisations sometimes remain visible, and the country usually is. The data still exists: registrars must keep it accurate and will disclose it for valid legal requests. To contact the owner, use the registrar’s contact form or the details on the website itself.
Does this work for .co.uk and other .uk domains?
Yes. Nominet runs a full RDAP service for .uk, .co.uk, .org.uk, .me.uk and the other second-level .uk extensions, and the tool reads it directly. You get the registrar tag, registration and expiry dates, status locks, nameservers, DNSSEC and the abuse contact. Nominet omits the expiry date for a few names it manages itself, and the tool tells you when that happens.
Why does the tool say a TLD has no RDAP?
RDAP is mandatory for generic top-level domains but optional for country codes, and registries such as .eu, .ie, .es, .it and .jp still offer only the old port-43 WHOIS service. Browsers can’t open raw TCP connections, so no web page can query it directly without a server doing it for you. The tool links the registry’s own lookup page instead.
How accurate is the expiry date?
It is the date the registry holds, which is the authoritative one. Some registrars show a slightly earlier date in their control panel because they renew or suspend ahead of the registry deadline, and the tool shows that separately as “registrar expiry” when the registrar publishes it. A domain renewed today may take a few minutes to show the new date.
What is the abuse contact for?
It is the address the registrar or network operator must monitor for reports of phishing, malware, spam and fraud. Send clear evidence: the full URL or headers, timestamps with time zone, and what harm it causes. For IP addresses, the regional registry’s abuse contact reaches the ISP or hosting company that can act against its customer.
Is my lookup logged?
Not by us. Your browser queries IANA and the registry’s RDAP server directly, so those servers see the lookup as they would any visitor. The few requests that go through our relay, for registries that block browsers, are passed straight through without being stored. Registries may rate-limit heavy use, and the tool tells you if that happens.