My partner and I are looking to purchase our first home together and we have quite different personal finances and credit histories.

I have a fairly high income and considerable cash reserves, but while in college I was not always the best with money, so my payment history is not pristine. I also do not have an extensive credit history. My FICO score is around 650.

My partner, on the other hand, has an impeccable credit history with ten years or so of steady credit line increases and a perfect payment record. He also has a mortgage now that he has paid on faithfully. His FICO score is much higher at around 800. He doesn't make as much money as I do or have as much cash on hand, but is still doing pretty well.

I have some student loans, but otherwise neither of us has any debt and our credit cards are paid off.

My question is how a lender will handle our differing credit histories. I assume that in terms of income and cash on hand, they will add our figures together and take the total. Is that true? But when it comes to credit score, how do they handle our different histories. Do they take his high score as a good thing? Do they take my lower score as a bad thing? Both? Would they treat us as an applicant with a score of 725 (the average of our scores)?

I am sure there is some complicated formula. I am just looking for a general idea of what to expect.