What is a certificate of …

A Certificate of Entitlement is the document that confirms an individual has the right to live in the UK permanently and is issued when you have been granted Indefinite Leave to Remain (ILR) in the UK. The Certificate of Entitlement is issued by the Home Office and includes the holder’s name, date of issue, date of expiry, photograph, passport number, biometric information, and ILR details.

Source: gov.uk