When are you eligible to apply for settlement / indefinite leave to remain?
What documents must be provided when applying for settlement?
The specific documents required will depend on what category you are settling in. However, most will require proof of residence, together with evidence you have passed the life in the UK test and taken a relevant English language test to at least level B1 CEFR.
How do I demonstrate a good understanding of the English Language?
Do I need to have original documents to apply for a UK visa?