Full British citizenship is one of six forms of British nationality. The definitions of citizenship are outlined in the British Nationality Act 1981. To live and work in the United Kingdom you must be a British citizen or a British subject who qualifies under the Immigration Act 1971. A UK passport is the greatest evidence of British citizenship.
Check if you are eligible for naturalisation. You can apply for naturalisation as a British citizen if you are over 18 and have lived in the United Kingdom for the last five years. This is reduced to three years if you are married to a British citizen or are in a civil partnership with a British citizen.
Choose which application process you would prefer. There are three ways to apply if you are already in the United Kingdom. The first is to apply through the Nationality Checking Service. This service, provided by local authorities, can accept your application form and forward it to the UK Border Agency. The UK Border Agency website lists the local authorities which provide the service. You can submit an application individually or through a representative who must be registered with the Office of Immigration Services Commissioner.
Complete the application form. The UK Border Agency website can direct you to the correct type of form depending on your status. Once you sign the form this is your declaration that you are of good character and in sound mind. Application costs vary but the website also provides an online fees leaflet which outlines the price.
Send the form. If you are in any part of the United Kingdom you must send the form and the fee to the UK Border Agency. If you are based in the Channel Islands, the Isle of Man or a British overseas territory the documents must be sent to the territory's relevant Governor. If you are currently anywhere outside these areas the application must be sent to the nearest British diplomatic post. There may be an additional fee to cover the forwarding costs.
Wait for acknowledgement of receipt of the application. This may take up to four weeks during busy periods. The UK Border Agency says that since January 2009 application enquiries may take up to six months to complete. The Agency makes a decision on 95% of applications within six months.
If successful you will be required to attend a citizenship ceremony. These are arranged close to where you are situated whenever possible. When you receive an invitation you have 90 days to attend the register office. Once in attendance you are required to make an oath of allegiance and a pledge. If you wish not to swear by God, you can make an affirmation of your oath and pledge.