It is possible to become a UK citizen in several different ways, as the United Kingdom has one of the most complicated immigration systems in the world.

Legal possibilities include:

  • Marriage to a British citizen (preferably one who was registered as such at birth). This confers the right to naturalise in little over a year. However, divorce within three years can affect citizenship.
  • Application for a job in the UK (especially in a sector where there is a skills shortage). The employer must then apply for a two year work permit. After 23 months they must request an extension to the work permit, which will normally only be granted for a further year. After another 11 months, the employer must again request an extension. Finally, after 4 years of legal residence in Britain, permanent residence rights are automatically granted. After another year the worker can apply for naturalisation.
  • Entering the UK and claiming asylum upon arrival. This may result in incarceration in a "detention centre" until the claim for asylum is processed, which can take a substantial period of time.
  • People with British ancestry may be allowed to become naturalised citizens, if one of their parents was registered as British at birth. The process of making an application on these grounds can take between three months and three years to complete.