This evening Nominet, the .uk Registry, will be conducting some maintenance that will affect WHOIS availability checks for all Registrars. During this time, any WHOIS and availability checks performed on .uk domains will fail. Any orders for new registrations and renewals submitted during this time period will be processed once the Nominet maintenance has completed.
Please note that this maintenance work will not affect service for any existing websites, which will all remain online throughout.
Further information is available on the Nominet website at https://registrars.nominet.uk/news/system-announcements/20-February-2019-business-continuity