The United Kingdom permits dual nationality without restriction. A British citizen who becomes an American keeps British citizenship, no permission is needed beforehand and nothing has to be reported. The harder question for families here is the opposite one: whether a child born in the United States is British at all.
Quick facts
The governing distinction is between a British citizen otherwise than by descent — typically born in the UK — and one by descent, born abroad to a British parent. The first passes citizenship to children born anywhere; the second generally does not.
How the generations work
| Parent’s status | Child born in the U.S. | Route |
|---|---|---|
| British citizen otherwise than by descent | British automatically, by descent | Apply for a passport directly |
| British citizen by descent | Not British automatically | Registration, where a route applies |
| British parent in Crown or designated service | Can be British otherwise than by descent | Special provision |
| Child who would otherwise be stateless | Specific entitlement | Registration |
Naturalisation, by contrast, requires residence in the United Kingdom. There is no route to become British by living in the United States.
How to proceed
- Establish how the British parent acquired citizenship, because that single fact decides the child’s position.
- If the child is British automatically, skip registration and apply for a first passport, which is itself the recognition.
- If the child is British by descent only through a parent who is also by descent, check the registration routes and their conditions.
- Gather the documentary chain: the parent’s full birth certificate, their parents’ details, and any naturalisation papers.
- Apply online and pay the Home Office fee for the relevant route.
- Once citizenship is settled, apply for the passport through the overseas service.
Required documents
- Child’s long-form U.S. birth certificate naming both parents.
- British parent’s full birth certificate, showing their own parents.
- British parent’s passport and, where relevant, naturalisation or registration certificate.
- Parents’ marriage certificate where the route depends on it.
- Evidence of Crown service where that provision applies.
- Proof of the family’s U.S. address.
Where to apply
Applications are made online to the Home Office and decided in the United Kingdom. Consulates play no part in citizenship decisions.
No offices currently listed.
Additional notes
A passport is evidence, not a grant
Issuing a passport confirms citizenship that already exists. It is never the mechanism by which someone becomes British.
Dates matter
British nationality law has been amended repeatedly, and entitlement is judged by the rules in force on the date of birth. Older family situations frequently turn on a change made decades ago.
Nothing is lost by naturalising in the U.S.
Acquiring American citizenship does not affect British citizenship, and there is no notification requirement in either direction.
Get advice for double descent
Cases where both the parent and grandparent were born outside the United Kingdom are the ones that most often need specialist advice before any fee is paid.