The UK Home Office has warned dual British nationals that after 25 February, they must carry a valid British passport to travel to the UK. Without it, they may be denied boarding flights, ferries, or trains. This follows a change in border control rules. Everyone traveling to the UK will need permission, such as an Electronic Travel Authorisation (ETA) costing £16, unless they are British, Irish, or exempt. Dual nationals face a new requirement to show their British passport. If they don’t, they must pay £589 for a certificate of entitlement to attach to their second nationality passport. Many say this fee is too high. A British woman in Germany, with dual nationality, said, "I’m really annoyed about being treated as Brexit collateral once again with this short-notice, shortsighted, arbitrary change of the rules." She worries about her children, especially her son traveling soon. Another British woman living in Spain for over 30 years took Spanish citizenship and renounced her British passport due to Brexit. However, presenting her British passport now could risk her Spanish nationality. She explained, "It seems a strange anomaly that while the UK is willing to recognise dual nationality, it refuses to recognise that a valid EU passport held by a UK citizen can give right of entry to the UK." James, a dual British-Italian national, booked a work trip to New York. He has only his Italian passport and was unaware of the new rule. He said, "I found myself having to travel at short notice and am now facing the idea that I may not be allowed back into the country." The certificate of entitlement has a long backlog, making it impossible to get in time. A Home Office spokesperson stated, "From 25 February 2026, all dual British citizens will need to present either a valid British passport or certificate of entitlement to avoid delays at the border." They added this is part of a digitisation program aimed at seamless travel and better immigration control. The 3 million, an EU citizens’ campaign group, called for a low-cost travel authorisation like Canada’s instead of the costly certificate. Monique Hawkins, head of policy and advocacy at The 3 million, said, "The UK already has the technology to do the same, so we urge them to act now to ensure British citizens are not locked out of their own country." If you are affected by the change and want to share your story, email lisa.ocarroll@theguardian.com.