Those who have lived in the UK unlawfully for 20 years or more can apply for leave to remain on this basis. The 20-year rule requires that a person has been residing in the UK continuously for at least 20 years without any long absences of more than 6 months.

One of the main requirements for this visa is evidence of continuous residence in the UK for the entire 20-year period. Tenancy agreements, utility bills, bank statements, employment records, medical records, etc, can be used to demonstrate evidence of continuous residence in the UK.