Naturalisation certificate prefix codes
This table explains the codes prefixed to British naturalisation certificate numbers.
| naturalisation act | year range | certificate prefix code | certificate type |
|---|---|---|---|
| Naturalisation Act, 1870 | 1870-1914 | A | Certificate (ordinary) to a person with five years residence in the U.K. during the eight years immediately preceding application for Naturalisation |
| Naturalisation Act, 1870 | 1870-1914 | AA | Certificate to person with five years service under the Crown during the eight years immediately preceding application for Naturalisation |
| Naturalisation Act, 1870 | 1870-1914 | AAA | Certificate to person in the Diplomatic or Consular Service with five years service under the Crown during the eight years immediately preceding application for Naturalisation |
| Naturalisation Act, 1870 | 1870-1914 | B | Certificate to person who has already been granted a Certificate of Naturalisation under the earlier Act of 1844 |
| Naturalisation Act, 1870 | 1870-1914 | C | Certificate to a person of Doubtful Nationality with five years residence in the U.K., or five years service under the Crown, during the eight years immediately preceding application for re-admission |
| Naturalisation Act, 1870 | 1870-1914 | D | Certificate of re-admission of person to British Nationality with five years residence in the U.K., or five years service under the Crown, during the last eight years immediately preceding application for re-admission |
| Naturalisation Act, 1870 | 1870-1914 | E | Declaration made by a person, a subject of a foreign state subsequently naturalised as a British subject, renouncing British nationality |
| Naturalisation Act, 1870 | 1870-1914 | F | Declaration by a person, an alien by origin but born within H.M. dominions, renouncing British nationality |
| Naturalisation Act, 1870 | 1870-1914 | G | Declaration by a person, born out of H.M. dominions of a father being a British subject, renouncing British nationality |
| Naturalisation Act, 1870 | 1870-1914 | H | Declaration by a natural-born British subject, renouncing subsequent Naturalisation in a foreign state |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | A and AZ | Certificate (ordinary) granted under Section 2 of the Act, where the names of children are not included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | B and BZ | Certificate (ordinary) granted under Section 2 of the Act, with the names of children included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | C and CZ | Certificate granted under sub-section (2) of Section 5 of the Act to a minor |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | D | Special certificate granted under Section 4 of the Act to a person with respect to whose nationality a doubt exists, where the names of children are not included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | DZ | Certificate of Naturalisation granted to a woman who was at birth a British subject and is married to a subject of a state of war with His Majesty |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | E | Special certificate granted under Section 4 of the Act to a person with respect to whose nationality a doubt exists, with the names of children included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | EZ | Certificate of Naturalisation granted to a woman who was at birth a British subject and is married to a subject of a state of war with His Majesty, with names of children included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | F | Certificate granted under Section 6 of the Act to a person naturalised before the passing of the Act, where the names of children are not included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | FZ | Certificate of Naturalisation granted to a French national where the names of children are not included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | G | Certificate granted under Section 6 of the Act to a person naturalised before the passing of the Act, with names of children included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | GZ | Certificate of Naturalisation granted to a French national with names of children included |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | M | Special Certificate granted under Section 4 of the Act to a person with respect to whose nationality a doubt exists |
| British Nationality and Status of Aliens Act, 1914 | 1915-1949 | O | Certificate granted under Section 8 of the Act by the Government of a British Possessions overseas |
| British Nationality Act, 1948 | 1949-1990 | BNA | Application made by a subject of a foreign state resident in the U.K. |
| British Nationality Act, 1948 | 1949-1990 | M | Application for registration of a minor child, under s7 & 18 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | O | Application made by a subject of a foreign state resident overseas |
| British Nationality Act, 1948 | 1949-1990 | R1 | Application made by an adult British subject or citizen of the Republic of Ireland, or any of the Channel Islands, Isle of Man, a colony, a protectorate or a protected state to which s8(1) of the Act applied, or a U.K. Trust Territory, or on the grounds of Crown Service under H.M. Government in the U.K., under s6(1) 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | R2 | Application made by a woman who has been married to a citizen of the U.K. and colonies, under s6 (2) 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | R3 | Application made by a foreign woman who has been married to a citizen of the U.K. and colonies, under s6 (2) 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | R4 | Application made by a person who but for his citizenship or potential citizenship of one of the countries mentioned in s1 (3) of the Act would have become a citizen of the U.K. and colonies under s12 (4) of the Act, under s12 (6) 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | R5 | Application to resume British nationality by a person who has ceased to be a British subject on the loss of British nationality by his father or mother in accordance with s12 (1) of the 1914 Act, under s16 1948 Act |
| British Nationality Act, 1948 | 1949-1990 | R6 | Declaration of renunciation of citizenship made by a citizen of the U.K. and colonies who is also a citizen of one of the countries mentioned in s13 of the Act or of the Republic of Ireland or a national of a foreign country, under s19 1948 Act |