Yes, both husband and wife's credit scores will be taken into consideration if both are to be named on the mortgage. Otherwise, whichever spouse is to be named on the mortgage would be the spouse/credit checked.
The FICO scores provided within the credit report determine many of the costs contained within your loan and determine the lending programs available to you for your purchase transaction. The higher the FICO scores, the less risk the lender believes is taken regarding your ability to repay the loan in a timely fashion. The higher the FICO scores, the more lenders there are willing to extend loans to you and take the risks involved in that lending. Your interest rates are tied directly to your credit scores also. The better your credit, the lower the interest rate you normally qualify for.
If this is your first home buying transaction, you are able to take advantage of the First-Time Home Buyer's Tax Credit (up to $8,000) presently being offered through the recent stimulus package. In order to benefit from this tax credit however, you must close on your home before December 1, 2009. Please be aware of that date for any upcoming purchase.
My suggestion is (especially if you are first-time buyers) ... speak to a reliable lending professional as soon as possible for pre-qualification of a mortgage. Through that pre-qualification procedure you will learn and gain much. Your lender will run a credit report to determine your current FICO scores at the time of the pre-qualification. It truly is the best place to start preparing for your upcoming home buying transaction. If any credit issues are found to exist in the credit report, it also alerts you to their existence. If needed, your lender will provide guidance to you as to how to proceed to best improve your credit and credit scores.
If you have other questions regarding mortgage financing, credit/debt issues, or purchasing a home, please do not hesitate to write.