Long residency concession requirements
The 20 year period excludes any period spent in the UK following service of notice of liability to removal or notice of a decision to remove.
There is no requirement to have held a valid UK visa. In other words, time spent in the UK may include illegal residency.
Once you have received this concession, you will be allowed to obtain a two and a half year residency visa, which you can renew three times (i.e. hold for a total of ten years). At the end of the ten years, you can then apply for indefinite leave to remain.
Someone who is aged over 18 but under 25 and has lived in the UK continuously for half their life can also apply under this route. As above, they will be given four sets of leave to remain for two and a half years. Once they have had leave to remain for 10 years they can apply for indefinite leave to remain.
These cases can be quite sensitive. Know that our experienced team will handle your application with the highest degree of professionalism and discretion.