Unless you can acquire British Nationality via your birth or decent, you will most likely need to qualify under the British Naturalisation process. The granting of a Certificate of Naturalisation is at the discretion of the Home Office and there are criteria that need to be met. All candidates must:

-  be over the age of 18;

-  not be of unsound mind;

-  be of good character;

-  have sufficient knowledge of English, Welsh or Scottish Gaelic (depending on their age and     physical and mental condition). Since 28th July 2004, individuals need to prove sufficient     knowledge of the English language.

-  stay closely connected with the United Kingdom

-  meet certain residency requirements *

* Residency requirements

You can meet the residency requirements in one of two ways - the 'five year rule', and the 'three year rule'. To qualify for the three year rule, you need to be the spouse of a British citizen.

Five year rule
The residency requirements to qualify for under the five year rule are as follows.

-  You must have been present in the UK at the beginning of the five year period. The five year     period ends the day the Home Office receives the complete application;

-  During that five year period your absences have not exceeded 450 days, of which no more     than 90 days can be in the last year immediately preceding the application submission date

-  You must have had indefinite leave to remain (permanent residency / no time limit) in the UK     for a period of at least 12 months prior to the application submission date;

-  During the five year period, you have not been living in the UK in breach of any UK     immigration rules

Three year rule

The residency requirements to qualify for under the three year rule are as follows.

-  You must have been present in the UK at the beginning of the three year period. The three     year period ends the day the Home Office receives the complete application;

-  During that three year period your absences have not exceeded 270 days, of which no more     than 90 days can be in the last year immediately preceding the application submission date

-  On the day your application is received by the Home Office you must have indefinite leave to     remain (permanent residency / no time limit on your stay);

-  During the three year period, you have not been living in the UK in breach of any UK     immigration rules

Please note that for either type of application process, you do not need to ensure that the application reaches the Home Office on the exact day you complete three or five years respectively. The application can reach the Home Office at any time after your qualifying period as long as you still meet the criteria listed.