If she is a signatory on the loan, she is as legally obligated for the payments as you are. If she will not pay her share, you could sue her to force her to contribute. That's the good news; the bad news is that a lawsuit, with its own attendent costs (e.g. legal fees) is the only way to do this. Still, for a home loan, the amount of money at stake is almost certainly enough to more than justify the cost of an attorney, so you should consult with a lawyer (note: many will provide a free initial consultation to evaluate whether a case is worth pursuing) to discuss the matter. Another option, which you could discuss with a family lawyer (such as whichever lawyer handled your divorce) is whether there is a way that you could pay the full amount, but take your ex's share as a credit against alimony, support, etc. that you may owe her. Good luck.