Here are seven requirements you need to meet before you apply:
Residential requirements
In order to demonstrate the residential requirements for naturalisation you need to: have been resident in the United Kingdom for at least three years (this is known as the residential qualifying period) before the date of your application; and have not spent more than 270 days outside the United Kingdom during the three-year period; and have not spend more than 90 days outside the United Kingdom in the last 12 months of the three-year period; and have not been in breach of the immigration rules at any stage during the three-year period.
Start of the residential qualifying period
The residential qualifying period will be worked out from the day that your application is received by the Home Office. 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 2002. 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.
Immigration time restrictions
You must be free from immigration time restrictions on the day you make your application. This often means having already gained settled status before you make your citizenship application. How and when you are eligible for settled status will depend on the immigration category you were in and successfully meeting its requirements for indefinite leave to enter or remain. For example spouses and civil partners of British citizens who must complete a 5 year probationary period under Appendix FM would generally have the opportunity to apply for naturalisation on this basis once they complete the 5 year period and obtain indefinite leave to remain provided they can also meet the other requirements of naturalisation at that time.
European Economic Area nationals and Swiss nationals
If you are a European Economic Area (EEA) national or a Swiss national or the family member of such a person, you will automatically have permanent residence status if you have exercised EEA free-movement rights in the United Kingdom for a continuous five-year period ending on or after 30 April 2006. You do not have to apply for leave to remain. If you have been outside the United Kingdom for six months or more in any one of the five years of the residence period you will have broken your residence. This does not apply if: the absence was due to military service; or all absences were for under 12 months and were for important reasons such as pregnancy, childcare, serious illness, study, vocational training or an overseas posting. If you leave the United Kingdom for a continuous period of two years or more you will lose your permanent residence status. If you have indefinite leave to remain (ILR) in the United Kingdom you will be considered settled providing you have not been away for two years or more since you received ILR.
Breach of immigration laws during residential qualifying period
You must have been in the United Kingdom legally throughout the residential qualifying period. We may refuse your naturalisation application if you have breached the immigration laws during the residential qualifying period. If you came to the United Kingdom as an asylum applicant, you would be considered in breach of the immigration rules if your application for refugee status and any appeals were refused during the residential qualifying period. You would also be in breach of the immigration rules if you entered the United Kingdom illegally and obtained refugee status during the residential qualifying period.
Absences from the United Kingdom during the residential qualifying period
During the residential qualifying period you must not have been absent from the United Kingdom for more than 270 days in the last three years. You must not have been absent for more than 90 days in the last 12 months. There is discretion to allow absences above the normal limits. For details of how we apply discretion, you should read the page on discretion when considering absences from the United Kingdom during the residential qualifying period.
Crown and designated service
If you are applying on the grounds of your husband's, wife's or civil partner's crown service rather than your residence in the United Kingdom you must show that: one the day you apply your husband, wife or civil partner is working outside the United Kingdom in crown or designated service; and your husband, wife or civil partner was recruited to that service in the United Kingdom; and your naturalisation would be in the interests of your husband's. wife's or civil partner's employing organisation; and if you are in the United Kingdom on the day you apply you must not be subject to time restrictions; and you were not in breach of the United Kingdom immigration laws during the three years immediately before applying; and your marriage or civil partnership has lasted more than three years. Marriage or civil partnership to a British citizen in crown or designated service is an alternative only to the residence requirements for naturalisation. You must still meet the other requirements for naturalisation.