Upvote:4
According to https://www.gov.uk/government/publications/biometric-residence-permits-overseas-applicant-and-sponsor-information/biometric-residence-permits-overseas-applicant-and-sponsor-information-accessible-version you have three months to notify changes to your personal details on your biometric residence permit
You must tell us as soon as you can if:
you change your name (for example, because of marriage or by deed poll);
you change your gender, legally or permanently;
you change your nationality; or
your facial appearance changes significantly.
If you change any personal details listed above or any details shown on your biometric residence permit, you must apply for a new permit within three months, by making an application for transfer of conditions (TOC) or no time limit (NTL). You can download the application forms and guidance at Transfer Visa
If you do not do this, you may have to pay a financial penalty of up to Β£1,000 or your permission to stay may be shortened.