How you file a tax return has no impact on your individual credit. But for a married couple to file separately will *automatically* disqualify you both for credits you might otherwise qualify for. It's almost always more costly tax-wise for a married couple to file separately. Also, if you live in a community property state, it probably won't matter how you "apply" for a loan, be it together as a couple, or separately on your own. The fact that you're married will have some amount of weight in the loan approval process. YOu need to talk to a loan officer now, and not wait until you "think" you're ready so you don't risk any surprises.