After you have been granted indefinite leave to remain in the UK, you may choose to become a British citizen. If you are the spouse of a British Citizen, then you may apply for naturalisation immediately after being granted an ILR.
There are certain residence requirements to be met whilst applying for naturalisation.
You should not have:
You would have to also prove enough knowledge of English at CEFR level B1 and Life in the UK (through KoLL test).
You would also be required to demonstrate that you are a person of good character – This is usually done by giving references (persons willing to vouch for your character) in support of your application.
After your naturalisation application has been granted, you would have to attend a ceremony in your local council (within 3 months), where you will be presented with the certificate of naturalisation and you would become a British citizen.