How to find out when a domain was first registered
Check WHOIS through your registrar or ICANN Lookup for the domain's creation date, then cross-check it against Archive.org's Wayback Machine, since WHOIS history can change after a transfer. The creation date is the single most important fact in a UDRP case: a domain registered before your trademark existed almost always defeats a bad faith claim.
Where do I check?
ICANN Lookup for generic domains. It shows the creation date, though privacy services now hide most individual registrants behind it. Your registrar's own WHOIS tool shows the same record.
Country-code domains run their own registries with their own rules about what is public. WIPO keeps a database of country-code domain practices that is worth checking before you rely on what a ccTLD's WHOIS shows you.
Cross-check both against Archive.org's Wayback Machine. It shows what the site looked like historically, which is separate evidence from the WHOIS date and useful where the WHOIS record itself has been changed.
Why does the date matter this much?
Because bad faith registration is judged at the exact moment of registration, not at any point since. If your trademark rights did not exist yet when the domain was registered, the registrant cannot have been targeting a mark that did not exist, however badly they are behaving with the domain now.
A domain registered in 2015, when your company was founded in 2021, is almost never a UDRP case. The three elements covers the narrow exceptions, and they are genuinely narrow.
What if the registrant changed hands?
A transfer can reset some WHOIS fields, including the "updated" date, without changing the original creation date. Panels have seen registrants and their advisers try to obscure this, and treat a documented pattern of doing so, alongside other conduct, as evidence of bad faith rather than an innocent administrative change: see how a documented history of targeting a mark was treated in Encyclopaedia Britannica, Inc. v. John Zuccarini, The Cupcake PatrolD2000-0330 WIPO decision, 2000.
If ownership genuinely changed at some point, the registration date relevant to a bad faith analysis can shift to the date of that transfer. This is a fact-specific question, not something to assume either way from the raw WHOIS record alone.
What should I do if the timing favours me?
Capture the evidence before you do anything else: a dated screenshot of the WHOIS record, an Archive.org capture, and the registrar's own record if you can get it. Sites and WHOIS privacy settings change quickly once a registrant suspects a complaint is coming.
Then read how to file a complaint before you contact the registrant directly. Reaching out first usually raises the price and can be used against you later.