After you have lived legally in the United Kingdom for a certain length of time (usually between two and five years), you may be able to apply to live here permanently, depending on the category of visa you have. You should see the appropriate category for more information on whether you can apply for permanent residence and the qualifying period for it. See Application types for details of categories that may qualify.
If your visa category is not listed in Application types, you may not be able to apply for permanent residence. If you are here on a working visa, the appropriate section of Working in the UK will tell you if it is possible to apply for permanent residence.
In order to apply for permanent residence, you will normally first need to show that you have enough knowledge of language and life in the United Kingdom.
You must not send us your application more than 28 days before the end of your qualifying period. If you do, we may refuse your application with no refund of the fee. However, you must make your application before your current permission to stay in the United Kingdom expires.
Standard requirements for Citizenship by Naturalisation:
To demonstrate the residential requirements for naturalisation you need to:
Start of the residential qualifying period
The residential qualifying period will be worked out from the day we receive your application. Most unsuccessful applications fail because the applicant was not present in the United Kingdom at the beginning of the residential qualifying period. You must make sure you meet this requirement before you make your application. For example, if we received your application on 25 November 2005, you would have to show that you were in the United Kingdom on 26 November 2000.
You cannot count time you have spent in the United Kingdom while exempt from immigration control as part of the residential qualifying period. If you are in the United Kingdom as a diplomat or as a member of visiting armed forces or if you are in any place of detention, you would be considered exempt from immigration control. This time would be treated as absence from the United Kingdom.
As of 11 February 2009, wait times for naturalization applications were reportedly significant, taking up to 6 months to complete. The UK Border Agency stated that this was occurring because of the widespread changes proposed to the UK Immigration Laws likely to take effect in late 2009”