They are not required to apply for a residence permit, or indeed have any documentary evidence of their ILR visa UK. Some benefits make it more convenient for people to do so.
Indefinite Leave to Remain (ILR) is an immigration status that allows the person holding it to live and work in the UK for an unlimited period, without the need to apply for an extension of the visa. If people are granted Indefinite Leave to Remain, they can leave and re-enter the UK without any restrictions on immigration. Unlike British citizenship, which is granted for life, in certain circumstances, an ILR Visa UK of an individual may lapse.
If people have Indefinite Leave to remain but they do not have a certificate to prove it, they can apply in the form of a Biometric Residence Permit (BRP) to validate this status. People can do this by applying for an administrative process called a no time limit (NTL).
They can also apply for an NTL if they previously held a passport that contained proof of their ILR but that was lost or stolen, or expired If people apply for a permit indicating their Indefinite Leave to Remain and have no written documentation of their ILR, the Home Office will search all their available databases and archives for any documents containing proof that an Indefinite Leave to Remain was given to them. They are not required to apply for a residence permit, or indeed have any documentary evidence of their ILR visa UK. Some benefits make it more convenient for people to do so.
Once the Indefinite Leave to Remain application is approved, people do not need a government department permission to take up new jobs or change their jobs. Also, any limits previously imposed on the hours or form of work will be removed. People, self-employed, may engage in any type of business or profession.
People will also be able to pay higher education tuition fees and apply for student scholarships, as long as people have been resident in the United Kingdom for at least 3 years before the first day of the academic year. If people have ILR, only if they are a qualifying Commonwealth citizen can they vote in UK national and local elections and referendums. The definition of a Commonwealth citizen is available on the website of the Electoral Commission. When people in the UK are given permanent leave to remain (ILR), they're just a few steps away from full British citizenship.
The amount of time it takes for people to qualify for that sought-after status depends on which UK visa they currently hold. If individuals are granted ILR, they are permitted to stay in the UK indefinitely. Though not yet British, they will enjoy nearly all the benefits of full citizenship. They will be eligible to apply for British citizenship after holding an ILR for one year.