Indefinite Leave to Remain (ILR) is the term which is used to present permanent residence visa in United Kingdom. You can apply for permanent residency in United Kingdom if you have stayed and work in United Kingdom continuously for 5 years. You can apply for ILR after staying for 5 years in United Kingdom and can live in United Kingdom for as long as you wish to.
There will not be any restrictions or limits on you while staying on permanent resident visa. You can work full time, do your own business, and study with this visa in United Kingdom. There is no time limit to stay in United Kingdom as well.
Qualifying for this visa is completely depends upon current immigration circumstances. You will get permanent residency in United Kingdom if you have shown commitment to United Kingdom while staying at temporary visa.
You should not leave United Kingdom and stay outside for longer than two years once you get your permanent residence status. You will need to stay in United Kingdom and consider United Kingdom as home to be a permanent resident of United Kingdom. If you don’t stay in United Kingdom as a home country and spend more time outside United Kingdom continuously, you might need to lose your permanent resident status.
You will be able to apply for United Kingdom citizenship one year after you get permanent residency and following all the terms and conditions of being a permanent resident in United Kingdom.
You can apply for permanent residency in United Kingdom if:
Lived and worked for continuously 5 years in United Kingdom
Lived with European Economic Area family member for 5 years continuously in United Kingdom
Lived as family member of a British Citizen in United Kingdom for 5 years continuously
Can get permanent residence even before 5 years if:
Lived with EEA family member who was working or doing business in United Kingdom, just before their death
Lived with EEA family member who was working or doing business but stopped due to retirement, incapacity, or moved to other state while having resident status and visit UK once a week.
You can apply for permanent residency while being in United Kingdom. You will need to pay £65 as visa application for this process. £19.20 will get charged for your biometric information as well.