To apply for British citizenship by descent, you first need to know whether you are already a British citizen automatically or whether you need to register through the Home Office. If a parent was a British citizen “otherwise than by descent” when you were born, you are already British and simply apply for a passport to prove it. If you fall into one of the groups excluded by older rules, or you are a child being registered by a parent, you submit a registration application on Form MN1, UKM, or UKF, pay the fee, provide documents and biometrics, and attend a citizenship ceremony.
Are You Already a Citizen, or Do You Need to Register?
This is the first question to settle, because it decides whether you fill in a form at all. A parent who is British “otherwise than by descent” acquired citizenship through a direct link to the UK: born there, adopted there, or naturalized there. A parent who is British “by descent” was born abroad and inherited citizenship from their own parent. As a general rule, only the first kind of parent can pass citizenship automatically to a child born overseas.1UK Parliament. British Citizenship and Passports
If you meet the automatic criteria for your date of birth, you do not register and you do not pay a registration fee. You apply for a British passport and the Home Office verifies your status from the documents you send.2GOV.UK. Automatic Acquisition (Accessible) – Citizenship Registration is the route when you do not qualify automatically but Parliament has given you the right to become British on application, or when a parent is registering a child. If you are not sure which side of that line you fall on, the GOV.UK tool “Check if you can become a British citizen” walks through the questions.3GOV.UK. Check if You Can Become a British Citizen
Which Form You Need
Three registration forms cover almost all citizenship-by-descent applications. The right one depends on your age, the sex and marital status of your British parent, and when you were born.
Form MN1: Registering a Child Under 18
MN1 is used to register a child under 18 as a British citizen. It covers children who qualify under the various registration provisions of the British Nationality Act 1981, and it is the standard form parents use when a child needs formal registration rather than automatic recognition.4GOV.UK. Form MN1 – Guidance
Form UKM: British Mother, Born Before 1983
Before January 1, 1983, British mothers could not pass nationality to children born abroad the way fathers could. Section 4C of the British Nationality Act 1981 corrects that, and Form UKM is how you apply. You are eligible if you were born before January 1, 1983, and would have become a Citizen of the United Kingdom and Colonies had women been able to transmit citizenship on the same terms as men at the time.5Legislation.gov.uk. British Nationality Act 1981 – Section 4C6GOV.UK. Register as a British Citizen (Form UKM)
Form UKF: Unmarried British Father
If your biological father was British but was not married to your mother, you may have missed out on citizenship you would otherwise have inherited. Form UKF covers this. You are eligible if you would have become British automatically had your parents been married. The route originally applied only to people born before July 2006, but it has since been expanded to include people born after that date.7GOV.UK. Register as a British Citizen (Form UKF)
What It Costs
Fees changed on April 8, 2026, and vary sharply depending on which route you use.8GOV.UK. Home Office Immigration and Nationality Fees, 8 April 2026
- Child registration on Form MN1: £1,000. If the child turns 18 while the application is being processed, a £130 ceremony fee is added at the point of decision.
- Standard adult registration: £1,540 plus a £130 citizenship ceremony fee, for a total of £1,670.
- UKM and UKF registration: only the £130 ceremony fee. These remedial routes were created to fix historical discrimination, and no application fee is charged beyond the ceremony cost.
Fees are not refundable if the application is refused. If you withdraw before biometrics are submitted or before you attend an appointment, you can request a refund of the application fee. The ceremony fee is refundable if you withdraw before a ceremony is arranged.
Documents You Will Need
Every application requires original documents. Photocopies and laminated documents are not accepted. At a minimum, expect to provide:
- Your full birth certificate. For births after January 1, 1983, it must be the version showing both parents’ details.
- Your parents’ birth certificates, which establish where your British parent was born and whether they qualify as British otherwise than by descent.
- A marriage certificate, if your claim depends on your parents being married at the time of your birth.
- Proof of your parent’s British nationality, such as a British passport or a Home Office certificate of naturalization or registration.
Any document not in English or Welsh must be accompanied by an official translation signed and stamped by a translator who belongs to a recognized professional organization.9GOV.UK. Applying for a Passport From Outside the UK – Guidance Notes (Accessible) Gathering these papers is often the slowest part of the process, especially where records are decades old or held in a country with inconsistent record-keeping. The Home Office expects you to obtain the evidence yourself.2GOV.UK. Automatic Acquisition (Accessible) – Citizenship
How to Submit
Most applicants apply online through the GOV.UK portal, uploading scanned copies of supporting documents and paying the fee electronically. You can alternatively have your original documents scanned at a UK Visa and Citizenship Application Services (UKVCAS) appointment.10GOV.UK. Apply for Citizenship if You Have a British Parent – Born Between 1983 and June 2006
If you live in the Channel Islands, the Isle of Man, or a British Overseas Territory, you submit a paper application by post. The postal route is also open to applicants elsewhere who prefer it.11GOV.UK. Register Child Under 18 as British Citizen (Form MN1)
Good Character
Most adult registration applications require you to show “good character,” meaning no serious criminal convictions, no immigration violations, and no deception in dealings with the Home Office. The requirement applies to anyone aged 10 or older at the time of application.12GOV.UK. Good Character Requirement (Accessible)
UKM applicants and applicants on certain UKF paths are exempt. Because those routes exist specifically to remedy discrimination against children of British mothers and unmarried British fathers, Parliament removed the good character barrier so affected people could register without additional hurdles. Standard MN1 applications for children under 10 are also outside the requirement.
After You Apply
Biometrics
You will normally be told to provide biometric information — fingerprints and a photograph — after submitting. Applicants in the UK attend a UKVCAS appointment run by Sopra Steria, which can also scan supporting documents.13GOV.UK. UK Visa and Citizenship Application Services Not every application triggers a biometrics appointment, particularly paper applications from the Channel Islands or British Overseas Territories.
How Long It Takes
The Home Office aims to decide most citizenship applications within six months. If yours will take longer, you should be notified before the six-month mark. Complex cases and applications requiring verification of overseas documents tend to take the most time.14GOV.UK. Apply for Citizenship if You Have British Nationality – After You Have Applied
The Citizenship Ceremony
Every successful applicant aged 18 or older must attend a citizenship ceremony and make an oath or affirmation of allegiance to the King and a pledge of loyalty to the United Kingdom. Your local authority organizes the ceremony, and you must attend within three months of receiving your invitation.15GOV.UK. Citizenship Ceremonies If you live abroad, ask the British embassy or consulate whether they can host it; if you are only temporarily overseas, you may be asked to wait until you return. You are not officially a British citizen until the ceremony is completed.16Legislation.gov.uk. Nationality, Immigration and Asylum Act 2002
If Your Application Is Refused
A refusal is not necessarily the end. If you believe the decision was made on an error of law, policy, or procedure, you can apply for an administrative review using Form NR, submitted by post to the Liverpool office. A fee applies. This is a review of how the decision was made, not a full rehearing of your case.17GOV.UK. Application for Review When British Citizenship Is Refused – Form NR
Your original application fee is not returned after a refusal. If you have new evidence that was not available the first time, you can submit a fresh application instead of asking for review.
Getting Your British Passport
Once you are registered, or once you have established that you are already British automatically, apply for a British passport. If you have never held one before, this is a “first British passport” application, which carries a few extra requirements.
From overseas, the fees from April 8, 2026, are £116.50 for an adult online application and £130 for a paper application.18GOV.UK. New Fees for Passport Applications A first passport requires a countersignatory: someone who has known you personally for at least two years, works in a professional capacity, lives in the UK, and holds a current British or Irish passport. They confirm your identity and certify one of your passport photographs. You also submit your registration or naturalization certificate, if applicable, along with any existing foreign passports.9GOV.UK. Applying for a Passport From Outside the UK – Guidance Notes (Accessible)