Sometimes it may become necessary to stay in the country longer than the period permitted by your visa. In such circumstances we recommend that you contact Tamsons Legal Services before your visa expires if you intend to apply for an extension. Holders of visitor visas cannot switch to other immigration categories and so must either apply for an extension of leave to remain or leave the UK when their permission as a visitor expires. It is a criminal offence to remain in the UK after your visa has expired.