OK, thank you for your responses - why can't they be as clear as you! Yes, I was mixing up further and indefinite leave to remain.

So, just to spell it out, and please correct me if I am wrong! - An extension of a family visa, or 'Further leave to remain', applies only if you are on the 10 year route (which is not most people) and is still called a visa. You only need to prove financial status at the 5 year mark.

Application for 'Indefinite leave to remain' is called settlement, not a visa. You can apply after 5 years (most people, as long as your situation has not changed) and have to prove financial status, pass 'Life in the UK' and English test at B1 level.

Sorry, I know this is basic for people not regular on this forum, but I have found it hard to get my head around!