This advice only applies to people holding British citizenship. Foreign/EU nationals might have success, but they’re likely to meet resistance and be asked to present ID from their native country (thereby proving that their name has changed there, too). In particular, the Passport Office have a policy that they won’t change the name on the British passport of a dual-national unless the holder proves that they’re changing their name on any other passports they hold, too (except under very special circumstances, at their discretion).

Banks – and everybody else! – don’t strictly have any legal obligation to accept ANY change of name document, regardless of its type and origin. However, it’s widely-accepted that they will. However, since the regulations of the GDPR/DPA2018, so long as you can get government records changed (passport, driving license, electoral roll, council tax, HMRC etc.), you can very easily demand that a bank updates your details under a “right to rectification” request. I.e. you can point out that the government accepts that your name has changed and require that they correct their records in-line with that, under threat that you’ll sic the ICO on them otherwise (who can fine them literally millions, although they probably won’t).

This aggressive stance was helpful in this case against Santander, which resulted in the customer (who used a deed poll from freedeedpoll.org.uk) having their record updated as well as receiving compensation and a promise that Santander would update their training documentation to ensure that these deeds poll are accepted in future.