This information should not be relied upon as legal or professional advice. Read the disclaimer.

Nationality advice: where to start

Many nationality enquiries – particularly those involving people from former colonies or with ancestral connections to the UK – come from constituents who really need professional legal advice. If in doubt, you should recommend that the constituent seek advice from a specialist solicitor or adviser. This may seem unhelpful, but a constituent will be helped much more by correct professional advice.  

Many common questions about British nationality law, such as eligibility for British citizenship, can be dealt with by signposting constituents to information available from the ‘British citizenship‘ pages on GOV.UK. For more technical guidance you may wish to consult the Home Office’s ​​​​Nationality guidance, which set out policy for officials handling nationality applications.

However, published policy guidance does not cover every possible scenario, and the information might not be the most relevant to the case you are dealing with. For these reasons, the UK Visas and Immigration and HM Passport Office correspondence channels for MPs will usually be the best way of dealing with specific enquiries. They can advise to a greater extent about how they handle different scenarios and give responses which are specific to the case you are dealing with. Contact details are available on the MPs’ hotlines list available on the Parliamentary intranet. [The hotlines list is an internal resource for use by Members and their staff].

What is British citizenship?

‘British citizenship’ is one of six different types of British nationality status. Generally speaking, the other types do not automatically give the right to enter and leave and live and work in the UK without being subject to immigration controls (‘the right of abode’).

Every British citizen is either:

  • a British citizen ‘otherwise than by descent’ (meaning they acquired citizenship in their own right such as through naturalisation or birth in the UK), or
  • a British citizen ‘by descent’ (meaning their eligibility for citizenship derives from their ancestors’ nationality status).

There is little practical difference between the two types of status, except that a child born overseas to a parent who is a British citizen by descent does not automatically become British at birth (subject to certain exceptions). This is because entitlement to British citizenship can usually only automatically descend to one generation born overseas.

Who automatically becomes a British citizen?

The ‘Types of British​ nationality‘ page on GOV.UK includes information about who automatically acquires British citizenship at birth. There is also a useful ‘Check if you’re a British citizen‘ tool.

Put very briefly, people born in the UK from 1 January 1983 automatically acquire British citizenship at birth if at that time one of their parents was a British citizen or an Irish citizen living in the UK.

People born to a parent living in the UK without an immigration time restriction (such as indefinite leave to remain status) also automatically become British citizens at birth.

People born overseas are only automatically British citizens if their British parent(s) were not also born overseas (subject to limited exceptions).

People adopted by a British citizen in a UK court automatically become British citizens. There are more specific requirements for people adopted overseas.

How else can you become a British citizen?

People who do not automatically acquire British citizenship at birth/adoption may be able to apply to become a British citizen on account of their residential or ancestral ties with the UK. The two main routes are naturalisation and registration.

  • Applying to naturalise as a British citizen is the most common route for adults, if they have been lawfully living in the UK and have permanent permission to stay.The GOV.UK page ‘Become a British citizen‘ sets out the eligibility requirements, including information about the life in the UK test.
  • Children and some categories of adults are eligible to register as a British citizen.The eligibility criteria for registration are slightly different to naturalisation applications. There is a guide on the GOV.UK page ‘Register as a British citizen‘.

How can a constituent apply for a British passport?

HM Passport Office is responsible for processing passport applications. Only people who have British citizenship (or another British nationality status) can apply for a British passport.

The ‘Passports‘ section on GOV.UK contains extensive information for applicants on topics including: eligibility for a British passport; how to apply; how much it costs; how long it takes; how to obtain an ’emergency passport’; and how to stop a child/vulnerable person from obtaining a passport.

HM Passport Office’s passports policy guidance contains more detailed information about particular scenarios and types of case.

Members of the public can also obtain general advice from HM Passport Office’s Passport Adviceline.

Your office can use the HMPO/UKVI joint MPs’ correspondence channels to resolve more detailed passport casework or policy issues. 


The Commons Library does not intend the information in this article to address the specific circumstances of any particular individual. We have published it to support the work of MPs. You should not rely upon it as legal or professional advice, or as a substitute for it. We do not accept any liability whatsoever for any errors, omissions or misstatements contained herein. You should consult a suitably qualified professional if you require specific advice or information. Read our briefing for information about sources of legal advice and help.