Naturalisation

Naturalisation after six years in the UK
If you are not married to a British Citizen you will need to meet the following requirements to apply for naturalisation:

You must be aged 18 or over and are not of unsound mind.
You must be of good character.
You should be able to communicate in the English language (or Welsh or Scottish Gaelic). There are exemptions to this requirement, for example if you are elderly or mentally handicapped.
You should intend to live in the UK or in Crown Service abroad (working directly for an UK Government organisation), or be employed by an international organisation of which the UK is a member, or be employed by a company or association established in the United Kingdom.
If you are not married to an UK Citizen you will need to meet the following residence requirements over the last six years.
You must have been living in the UK exactly six years before the date the application reaches the Home Office; and During the six-year period you must not have been outside the United Kingdom for more than 450 days (about 15 months); and During the last 12 months of the six-year period you must not have been outside the UK for more than 90 days; and During the last 12 months of the six-year period your stay in the United Kingdom you must have held permanent residence/ indefinite leave to remain (ILR); and You must not have been living in the United Kingdom in breach of the UK immigration rules at any time during the six-year period ending with the date that the application is received by the Home Office.

Naturalisation after three years in the UK as a spouse of an UK Citizen

The requirements for naturalisation as a spouse of a British citizen are very similar to those mentioned above. The main difference is that there is a shorter residency requirement of three years in the UK as opposed to six years. The three years of the residency requirement are counted from the date your naturalization application is received by the Home Office.
Further details on residency requirements are as follows:

The processing times for naturalisation applications is currently about six to seven months. If you would like assistance with a naturalisation application made on the basis of having permanent residency, please contact us

You must have been living in the United Kingdom at the beginning of the three- year period; and
On the date that your application is received in the Home Office, you must have permanent residence/ ILR in the UK; and
During the three-year period you must not have been outside the UK for more than 270 days (approximately 9 months); and
During the last 12 months of the three-year period you must not have been outside the UK for more than 90 days; and
You must not have been in breach of any UK immigration rules at any time during this three-year period of residence in the UK.