Sued for a Joint Debt After Separation in Ontario
If you signed for a debt jointly with your ex-spouse or partner — a credit card, a line of credit, a joint car loan — and your separation agreement says “he keeps that one” or “she’s responsible for the LOC,” that promise is between the two of you. It is not a promise the creditor ever agreed to. If your ex stops paying, the bank or collection agency can still sue you personally for the entire balance, serve you with a Statement of Claim, and get a judgment against you — regardless of what your separation agreement says. Here is why that happens, what your separation agreement actually protects, and what to do if you are the one who gets served.
Why the Creditor Can Still Sue You
When two people jointly sign for a debt, each of you is typically liable to the lender for the full amount, not half — a concept lawyers call joint and several liability. Your separation agreement is a domestic contract between you and your ex, governed by Part IV of Ontario’s Family Law Act. It can validly require your ex to “assume” the debt and pay you back if you’re ever forced to cover it, but it cannot rewrite the deal you both made with the bank when you opened the account. The creditor was never a party to your separation agreement and never agreed to release either of you — so from its perspective, nothing has changed: both names are still on the account, and it can pursue either or both of you for the full amount owed, exactly as it could before you separated.
Joint Debt vs. “Who Pays” Are Two Different Questions
It helps to keep these separate. Question one: who does the creditor have the legal right to collect from? Answer: both of you, jointly and severally, for as long as both names remain on the account. Question two: as between you and your ex, who is supposed to bear the cost? That is whatever your separation agreement says, and it is enforceable — but only between the two of you, through Family Court or a civil claim for breach of contract. A separation agreement resolves question two. It does nothing to question one. That mismatch is exactly what catches people off guard when a Statement of Claim shows up, naming a spouse who thought the debt “wasn’t theirs anymore.”
What to Do If You’re Served With a Statement of Claim
Treat it like any other debt lawsuit: you generally have 20 days to respond if you were served in Ontario, and ignoring it risks a default judgment against you, with no separation-agreement defence available to undo it after the fact. Read the claim closely to confirm the amount, the creditor’s identity, and whether it was filed within Ontario’s limitation period, since debt that’s too old to sue on is a real defence, while “my ex was supposed to pay this” is not one the court will accept as an answer to the creditor’s claim. You still need to file a Defence on time to avoid being noted in default — the separation agreement becomes relevant afterward, in how you deal with your ex, not in whether you owe the creditor.
Can You Pull Your Ex Into the Lawsuit?
Possibly, and this is where it’s worth involving a lawyer or licensed paralegal quickly. Ontario’s Rules of Civil Procedure (Rule 29) let a defendant issue a third party claim against someone not already named in the suit — including an ex-spouse — for contribution, indemnity, or a “remedy over” connected to the same debt. If your separation agreement has your ex assuming this exact debt, that assumption clause is the basis for arguing your ex should indemnify you for whatever the creditor recovers from you. Ontario’s Mercantile Law Amendment Act also recognizes, as a general principle, that co-debtors shouldn’t end up paying more than their fair share relative to each other. None of this changes what you owe the creditor, and a third party claim adds cost, complexity, and time to your defence, so it’s a strategic decision, not an automatic step. Your lawyer or paralegal can tell you whether it belongs inside this lawsuit or is better handled afterward as a separate claim against your ex for breach of the separation agreement.
Protecting Yourself Going Forward
If you still hold any joint accounts with an ex, the safest fix is closing them or refinancing the balance into one name, with the creditor’s agreement — not just an internal understanding. A separation agreement can promise a refinance will happen; it cannot force the bank to release you from an account it never agreed to release you from. Until an account is actually closed, transferred, or paid off, both of your names — and your credit — stay exposed to whatever happens on it, including charges your ex makes after you’ve separated.
Frequently Asked Questions
My separation agreement says my ex is responsible for this debt. Can I show that to the court as a defence? No. It’s not a defence to the creditor’s claim, because the creditor isn’t bound by an agreement it wasn’t part of. It can matter for a separate claim against your ex, but not for whether you owe the money to the creditor who sued you.
If I end up paying, can I get the money back from my ex? Generally yes, if your separation agreement has your ex assuming the debt — that’s a breach of contract claim, or potentially a third party claim inside the same lawsuit. Talk to a lawyer or paralegal about which route fits your timeline and budget.
What if I only guaranteed my ex’s loan and it was never in my name? A guarantee is its own direct promise to the creditor, separate from the separation agreement, and it typically survives separation the same way a joint debt does — the creditor can call on you as guarantor regardless of what you and your ex agreed between yourselves.
Does it matter if my ex kept using the joint card after we separated? It can matter for how much your ex owes you back under the separation agreement, but it generally doesn’t change what the creditor can collect from either of you — the account is still joint until it’s closed or transferred.
If You’ve Been Served, Don’t Wait
A Statement of Claim over a joint debt is stressful precisely because it feels unfair — you did what your separation agreement said, and you’re still the one being sued. Tell us what you’re dealing with, and we’ll help you sort out your deadline, your defence, and whether pursuing your ex makes sense alongside it.
Sources: Limitations Act, 2002, S.O. 2002, c. 24, Sched. B · Family Law Act, R.S.O. 1990, c. F.3 (Part IV, Domestic Contracts) · Rules of Civil Procedure, R.R.O. 1990, Reg. 194 (Rule 29, Third Party Claims) · Mercantile Law Amendment Act, R.S.O. 1990, c. M.10 · Small Claims Court, Ministry of the Attorney General. General information for Ontario, not legal advice.
General information for Ontario, not legal advice. Reviewed by Angelos Spingos. Last reviewed September 17, 2026.