Over 80,000 UK-run websites have been plunged into a blackout following a culling of EU domain names after Brexit.
EURid, which manages the European Union domain name, has suspended the .eu websites under new rules that came into force on 1 January.
The stringent new regime means that all existing UK-registered .eu domains have been suspended, and will no longer function for services such as websites and email.
From April, any remaining domains will be withdrawn, while from 1 January 2022 they will be revoked and become available for general registration.
Suspended domains can be reinstated before April if they are updated to meet the eligibility criteria, which requires showing evidence that a business or individual is registered, resides, or has citizenship in an EU member state.
EU citizens residing in the UK are still entitled to hold an .eu domain provided they update their registration information with their EU citizenship.
The overhaul, which was first reported by Computing.co.uk, follows a lengthy period of wrangling over whether Brits would still be entitled to hold EU domains following Brexit.
Under initial plans drawn up in 2018, the EU said it would cancel all websites registered to British individuals and companies.
But following a backlash from Brits and EU citizens, the bloc revised the rules to allow for some exceptions.