I think looking at the following
https://www.mbs-intermediaries.com/media/1099/broker-online-quick-guide-mortgage-lending-criteria-july-2018-mlc-07_18_1.pdf
- Your 4.5 x income puts you at just over £200k so with your debts, it may still be possible for you to borrow this amount on your salary alone. The criteria for zero hours and self employed are covered but doesn't specifically mention contractors.
If you have not used a broker to date in the application then I would suggest the following;
- Speak with the lender and update them on the change of circumstances.
- If they cannot continue with the application then go and see a broker who will be able to find you a lender that can. The figures look achieveable on face value but with contract workers - this is likely to be a specialist area but given that there is no previous experience in contracting or that field of expertise then this may be tricky but Im not a broker so cannot say either way.
In terms of both being on the mortgage - Im sure that should be OK because it's like a stay at home partner situation - they may not have income that can determine the affordability but they will be named on the property/deeds/mortgage - this gives the lender added security of having 2 people to chase if it all goes wrong.
You really need to just update the lender and take it one step at a time. I am sure that there is a good chance you will be fine but if not, you will have options I am sure if you consult a broker ahead of the next application.