No matter how well you are matched for each other, it's unlikely that your credit score is going to alight perfectly with your spouse's. You each have different histories when it comes to debts and paying back loans. But when you apply for a mortgage, a severe imbalance between the two scores can be troublesome.

Chris Birk, writing for the financial site Credit.com, says each spouse retains an individual credit score even if you have merged your finances after marriage. Dan Rafter, writing for the mortgage site HSH.com, says lenders also won't average the credit scores when considering your loan application.

However, the mortgage will still be considered based on the worst score of the two. Even if one score is at or near the perfect 800, the mortgage application may be rejected because of the lower score. Even if you do get approved, the lower credit score will result in a mortgage with a higher interest rate.

Kimberly Lankford, writing for the financial site Kiplinger, says you'll qualify for the best interest rate if both your score and your spouse's score are above 740. If one score is at 620 or lower, you may not be able to qualify for a mortgage.

Discussing the issue with the lender might be helpful. Amber Keefer, writing for SFGate, says you can mitigate your credit score by demonstrating financial stability in other ways, including a sound income history and the ability to make a large down payment. If the low credit score is a result of a past period of unemployment or illness, you can explain this to the lender as well.

Another option is simply to leave the spouse with the poor credit score off the mortgage application, allowing you to benefit from the higher score. Rafter says that this will not affect ownership of the house, since it is possible to list both spouses on the title.

Making a single rather than a joint application does have its downside, however. The lender considers your debt to income ratio in approving a mortgage, and prefers to keep this ratio at or below 36 percent. Since your spouse's earnings cannot be considered in a single application, you might not be able to meet this threshold. In this case, you may have to consider applying for a smaller loan or looking at less expensive properties.

Birk says factors other than the credit score can also make a lender reluctant to approve an application with your spouse's name on it. If they have filed for bankruptcy or suffered a foreclosure or short sale, they'll have to wait until a "seasoning period" has passed before they can be considered for any other loans. Even if the spouse's name isn't on the loan, the lender might be reluctant to approve a mortgage during the seasoning period.

You might consider delaying your application for a loan until your spouse can improve his or her credit score. Rafter says that the score can be significantly increased within a year by simply paying bills on time, using credit lines responsibly, fixing credit report errors, and getting rid of any disputed accounts.

Keefer says you can also ask for a parent or friend with good credit and income to assist you with the mortgage application by signing as a co-borrower. However, it might be difficult to find someone who is willing to do so. Since the co-borrower agrees to make any payments that the primary borrower misses, they're at considerable risk if you can't meet your mortgage obligations down the road.

Lankford says that you can also simply go ahead with the mortgage, even if it is approved at a less advantageous rate due to one spouse's lower credit score. As long as you make timely payments on the mortgage, your own credit score will be unaffected and your spouse's credit score will improve.