If you have credit in your name, and your spouse has credit in their name, and only one has financial problems, it's an easy decision that only the one that has financial problems should file bankruptcy. Getting married does NOT mean that your credit files are somehow "merged." The only thing that causes both of you to suffer, when one spouse has financial problems, is if you have joint credit accounts, credit expert Phillip Tirone explains in this recent blog post, "Marry Your Spouse, Not Their Credit Score."
Many times, people come into my Houston law office and only one spouse wants to file bankruptcy, so that they can "preserve the other spouse's credit." Well that is fine, if all of the debts that will be discharged are in the spouse-to-file's name. But if people have been married a long time, it's common that they have one or more "joint" accounts, on which they are both equally liable. And it's not a good idea, as Mr. Tirone explains in this article, for only one spouse to have credit, period. Both should have some credit, in case something happens to the other spouse.
In my experience, if the debt or a substantial part of it is joint debt, it is better for both spouses to file bankruptcy. After bankruptcy, I offer all of my clients Mr. Tirone's "7 Steps to a 720 Score" credit rebuilding program. If you follow his instructions, you can rebuild a 720 or higher credit score, within 12 to 24 months after your bankruptcy discharge.