Whether you are applying for leave to remain in the UK or have obtained leave to enter and are now extending your visa, you may have heard of both the 5-year and 10-year routes.
The primary difference is that if the Home Office decides that you meet all of the requirements and for leave to remain under the Immigration Rules, then you will be placed on the 5-year route. This means that the first visa which you have been granted is valid for two and a half years and then before this visa expires, you will apply for another visa that is valid for the same amount of time. Once you have completed five years on this route legally, you will be eligible to apply for Settlement, provided that you meet all of the other requirements for settlement.
If you are already in the UK and are applying to extend your visa, if the Home Office decides that you do not meet one of the requirements i.e., the English language requirement, but would find it unduly harsh to refuse your visa, then they will likely put you on the 10-year route to settlement. This means that you will be eligible to apply for settlement once you have legally completed 10-years on this route.
It is important to remember that if you are already on the 5-year route but happen to be switched on to the 10-year route or, you are on the 10-year route but begin to meet all of the requirements so decide to switch on to the 5-year route, then your clock to settlement will restart. For example, if you have completed 2 and a half years on the 10-year route but then switch on to the 5-year route, you will become eligible to apply for settlement after 5 lawful years rather than a further 2 and a half, because your clock will have restarted. However, it does mean that you can become settled quicker than if you were to remain on the 10-year route.