Overview If you have just been accepted for naturalisation or granted British Citizenship, you must attend a citizenship ceremony. Usually, you must do this within 3 months of being given approval. We are aware that the letter you receive from the Home Office advises you to contact us within 21 days. However, this will not be necessary as we are also advised by the Home Office when you have received a letter and we will contact you automatically. The details of ceremony options will be sent to you by post or email shortly after you receive your letter of approval from the Home Office.