Are Common-Law Partners Responsible for Each Other's Debts in Ontario?

Your partner racks up a credit card balance in their own name, or falls behind on a car loan they took out before you moved in together. Does any of that become your problem? Many common-law couples in Ontario worry it might, especially after hearing how differently property and support can work once you're "common-law." The short answer is reassuring for most everyday debt — but there are real exceptions worth understanding before you sign anything jointly. This guide explains common-law partner debt responsibility in Ontario, for existing debt, new debt, and the mortgage on a shared home.

The General Rule: Debt Follows the Name on the Agreement

Ordinary contract law, not family law, governs who owes a debt. Whoever signed the loan, credit card application, or lease is the one legally on the hook to the lender or landlord. A creditor generally cannot pursue your partner's individual debt from you simply because you live together, share a last name informally, or have been a couple for years.

Living Together Doesn't Change Who Owes What

Married spouses in Ontario share, through the Family Law Act's equalization process, in the growth of net family property when a marriage ends — but that's a calculation between spouses, not a rule that makes one spouse personally liable to the other's creditors. Common-law partners fall outside that equalization scheme entirely. There's no legal mechanism that pools your debts together just because you moved in together, however long you've been under the same roof.

When You DO Become Responsible: Joint and Co-Signed Debt

The exceptions come from what you actually sign, not from your relationship status:

• Joint bank accounts with overdraft privileges — both account holders can be liable for the overdrawn amount
• Joint credit cards, where you're a co-applicant rather than just an authorized user
• Co-signing or guaranteeing a loan for your partner, which makes you responsible if they don't pay
• Joint lines of credit
• A lease you both signed, which typically makes both tenants liable for the full rent

Authorized user vs. co-applicant

This distinction gets confused constantly. Being able to use a card is not the same as being contractually responsible for its balance — that depends entirely on how the account was opened.

What About the Mortgage on a Home You Share?

Mortgage liability and property title are two separate legal relationships, and it's easy to mix them up:

• If only one partner signed the mortgage, only that partner is contractually liable to the lender — regardless of who lives in the home, or whose name is on title.
• If both partners signed the mortgage, both are liable to the lender for the full amount, regardless of who actually makes the monthly payments, and regardless of what happens if the relationship later ends.
• Being on title without being on the mortgage doesn't create loan liability. Being on the mortgage without being on title doesn't create ownership.

Sorting out which of these applies to your situation matters before you assume either "I'm not on the mortgage, so I'm fine" or "I've been paying it for years, so it must be partly mine."

Practical Steps Before You Combine Finances

• [ ] Understand exactly what you're signing before co-signing or guaranteeing anything
• [ ] Keep records of who pays for what if you split shared household costs
• [ ] Consider a cohabitation agreement that addresses debt and expense-sharing explicitly
• [ ] Review any joint accounts or credit products before moving in together
• [ ] Get independent legal advice before guaranteeing a partner's business or personal loan

Frequently asked questions