If you're married, you might share household chores and expenses. But you can't share credit scores.

Each spouse has their own, distinct score and lenders will not average the two. If you put both names on a mortgage application they'll use the lower score to determine whether you qualify for a loan and what interest rate you'll pay.

That won't matter if the two scores are 740 and 720. But it will make a huge difference if one partner is 740 and the other is 580 -- a score that lands him or her in the high-risk, high-cost category of subprime borrowers.

If you don't have the means or time to repair that low credit score, you might be better off having the spouse with the highest credit score apply on their own. You'll have a better chance at getting a loan and a good interest rate.

The only drawback is that lenders will only consider that spouse's income when deciding how much you can borrow. That could be a problem if the spouse with the best credit score doesn't make most of your family's money.

You can use one of our mortgage calculators to determine how much income you'll need to qualify for the loan you want.