Change to Contractor & Re-newing Mortgage

[BroadWay81]

Hi all, I’m after some advice regarding contracting and mortgages. I’m thinking of going from full-time employed to working on a freelance basis. The timing of making this decision will depend on the mortgage situation. My two year fixed rate mortgage comes to an end May-16 and switches to a standard variable rate, which is nearly double the current rate!

Ideally I’d like to commence contracting before May-16. Does anybody know whether my existing mortgage provider would require proof of income if I were to obtain another fixed term product with them at that point?

Any help appreciated, thanks