Mortgage application wife has bad credit

Hi there,

I really need some advice. I have a good credit score of 999 my wife has really bad credit. So we thought we could simply complete a single application on me. The maths work out fine but the postoffice declined me. When they called to let me know they said they also check my financial associations. While she did not say much more she did say that everything else looked ok.

Will all lenders check my wife and if not who should we talk too?

Thanks in advance

John