contact the Inland Revenue and ask for your last 5 years earnings history called i think, SA302 slips.
They will send them out and they prove you are econimically active. YOu don't need to prove that you earn greater than 40K.
I did this last week and got my ILR.

Hi, I thought I might run through my ILR application with you all as there can be some misinformation out there. In particular, I want to clarify how pay is included for contractors using umbrella companies/schemes and the calculations for days abroad. Firstly, my application was successful, receive...