How to look for records of... Naturalised Britons

How can I view the records covered in this guide?

View online

How many are online?

  • None
  • Some
  • All

Order copies

We can either copy our records onto paper or deliver them to you digitally

Pay for research

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This is a brief guide to finding records of a naturalised Briton. It is intended to help you find information about somebody who came to Britain in the past.

For information on how to obtain a copy of a certificate of British nationality between 1 January 1949 and 30 September 1986 or a naturalisation issued between 1 January 1981 and 1 January 1986, please read Certificates of British citizenship instead.

What do I need to know before I start?

If immigrants came to Britain from Ireland or the British colonies they were called Britons. If they came from elsewhere (including Scotland before 1707) they were called aliens.

Foreigners wishing to become English (or later, British) could either apply for denization (which made them almost equivalent to native-born Britons and granted them most of a free subject’s rights and the protection of the law) or naturalisation (which granted them all the rights and made them a subject of the Crown). However, most foreign settlers did not bother to go through these formalities and so do not appear in these records.

Before the mid-20th century Britons from across the world were British citizens. After the British Nationality Act 1948, colonial Britons had to register British citizenship.

There is more information in the background papers to the applications than on the certificates themselves. Many are name searchable in our catalogue.

What records can I see online?

Naturalisation certificates and declarations of British nationality (1870-1912)

Search and download (£) naturalisation certificates and declarations of British nationality (HO 334) from 1870 to 1912 from Usually these list the immigrant’s:

  • name
  • residence
  • birthplace
  • age
  • parents’ names
  • name of spouse (if married)
  • occupation
  • children and their names (if still of dependent age)

Naturalisation case papers (1801-1871)

Search and download (£) naturalisation case papers (HO 1) for 1801-1871 from our catalogue. Usually these list the immigrant’s:

  • name
  • residence
  • birthplace
  • age
  • occupation

Census records (1841-1911)

Search census records (£) for England and Wales from 1841 to 1911 online. Note that many people called themselves naturalised British subjects in the census when they were not.

What records can I find at The National Archives at Kew?

Naturalisation case papers (1872-1934) and duplicate naturalisation certificates (1870-1982)

Search Discovery, our catalogue for case papers (HO 45, HO 144, HO 382) and naturalisation certificates and entries (HO 334, HO 409). Certificates include those issued to foreign nationals in the UK (1870-1980) and abroad (1915-1982). Certificates up to 1912 can be viewed online (see above).

Search by name followed by nat* for example Michael Marks nat*. Sort your search results by date.

You cannot search by name for Registrations of British Nationality 1949-1981, or Naturalisations, 1982-1986. Please read Certificates of British Citizenship for information on how to get a certificate.

Naturalisation case papers (1934-1996)

Search our catalogue (HO 405) by last name for naturalisation case papers.

Files may also contain later correspondence, mostly until the mid-1960s but some as late as 1996.

The documents are subject to 100 year closure (although access can be requested under the Freedom of Information Act 2000) and only about 40% of applications in this series have survived.

To access these records you will either need to visit us, pay for research £ or, where you can identify a specific record reference, order a copy £.

What records can I find in other archives and organisations?

Huguenot Society records

Consult the Huguenot Society website, which includes information about their archives and details of publications to help you trace individual immigrants, including indexes of naturalisations by private Act of Parliament up to 1800.

What other resources will help me find information?


Search Parliamentary papers (institutional subscription required) for indexes of all naturalisations from 1844 to 1961.


Search The National Archives’ bookshop to see whether any of the publications below may be available to buy. Alternatively, look in The National Archives’ library catalogue to see what is available to consult at Kew.

Roger Kershaw, Migration records (The National Archives, 2009)