Most UK banks accept a deed poll as the sole document required to change the name on an account. The process varies by bank — some require you to visit a branch in person with your original signed deed poll (or a certified copy), while others allow you to upload a copy through their mobile app or send it by post. It is worth checking your specific bank's process on their website before you go in, as waiting times and requirements differ.
When you change your name with a bank, they will update your account records and typically issue new debit and credit cards in your new name. Your account number, sort code, and online banking login do not change. Direct debits and standing orders continue uninterrupted — you do not need to notify your payees individually, as the bank account number they pay to stays the same. However, if you have a joint account, both account holders may need to attend in person.
It is sensible to update your bank account early in the name change process, as your bank card is often used as ID for other purposes. Once your bank card is in your new name, you have updated photo ID that can help when dealing with other organisations. Give yourself plenty of time between submitting the deed poll and needing your new card, as replacement card production typically takes 5–7 business days.