Indefinite leave to remain is a type of immigration status in the UK, the possession of which allows the person to live in the UK for an indefinite or limitless period of time. In some other cases, however, an indefinite leave can also mean a long term leave of more than 12 weeks, which does not specify an exact date the person is going to be returning to work, as they may have a condition they need to take care of which does not have any set time limits.