Learn What is Indefinite Leave to Remain UK You might be qualified to apply for Indefinite Leave to Remain UK if you have lived in the UK for the required amount of time under an immigration category that leads to settlement (ILR). With ILR status, you can work, study, and conduct business at any time without being subject to any restrictions on your stay in the UK. ILR is a requirement as well when requesting British citizenship. What is Indefinite Leave to Remain (ILR)? For foreign nationals, Indefinite Leave to Remain UK (ILR) is a type of settlement. In most cases, you must have lived in the UK for at least five years before you may apply for Indefinite Leave to Remain, However, in some circumstances, you can do so after only three or even two years. Innovator, spouse, and skilled worker visas are just a few of the immigration visas that might result in ILR. One can live in the UK without any limits with Indefinite Leave to Remain, which is the first step toward registration and full citizenship.