Could I Be Liable For Child Support to My Spouse’s Ex? 


Child support is the right of the child and the obligation of the parent.  So, the quick answer to whether one spouse has to pay the other spouse’s child support is “no". But, like most things in the law, things can be more complicated than that.

Child support is always payable by a biological or adoptive parent that has a child for 50% of the time or less.  (Where there is “shared parenting”, the amount of child support can vary from the child support tables, but usually both parents pay table child support to each other).   For more about how child support works watch the video below, and listen to this podcast.

In Ontario, getting married does not mean one spouse “owns” the other spouse’s assets nor does it mean one spouse is  responsible for the other spouse's debts - including any debts for child support.  Under Ontario Law, married spouse are still legally independent from each other.  Part 1 of Ontario’s Family Law Act covers property division on separation. For a full explanation of how that works, watch the video below, and listen to this podcast.   But to summarize, separated married spouse share in the increase in each other’s net worths, but not in the actual assets themselves.  Common-law couple have even fewer property rights.  So, if your fiancé is in debt to his ex for child support, that is not your debt. 

However, unfortunately, that may not be where it ends.  There are still ways that one spouse could end up “on the hook” for the other spouse's child support debt.

Ontario Family Law Podcast

9 - Property Division in Ontario After Marriage

10 - Child Support - Who Pays and How Much?

12 - How Step Parents and Grandparents Can Have to Pay Child Support

29 - Common Law Separation and Property Division

33 - The Law of Marriage Contracts & Cohabitation Agreements


53 - How to Pay Less Child Support

First, with regard to property division, when married spouses separate, they share in the increase in each other's net worth. When a married spouse builds up a child support debt, that debt decreases his or her net worth.  So, on separation, that net worth is lessened by the amount of the child support debt.  Since, on separation, each spouse essentially gets half of the other spouse’s increase in net worth, any debt owed by one spouse reduces how much the other spouse will get by half of the value of that debt. 


Put more directly, the spouse without the child support debt ends up indirectly paying half of that child support debt because of the decrease in what the other spouse shares through Ontario’s Property Equalization process. 

But, things can even work out worse than that if the spouse who owes the child support is also the spouse whose net worth has gone up less (or not at all).   The spouse with the greater increase in net worth during the marriage owes the other spouse an “equalization payment” on separation.  If the spouse who owes child support has a lower increase in his or her net worth (either because of the child support debt or otherwise), the other spouse will have to a larger equalization payment. So, when one spouse has his or her  net worth is decreased by child support debt, how much the other spouse owes for an equalization payment owe would be increased by half the amount of that debt.  In that case, the other, “innocent”,  spouse is indirectly, paying half of that child support debt. 

These types of debt problems, which can have very unfair results, can be fixed with a marriage contract.  Watch the video below on how to use a marriage contract to avoid sharing in your spouse’s debts.  Spouse can have a contract that says one spouse’s child support debts will not affect Property Equalization if the spouse’s separate.  That means the marriage contract can legally prevent one spouse from ever being responsible for the other spouse’s child support.

There is another way one spouse’s child support for their children of a previous relationship can become a problem for his or her current spouse.                                                                                                                                                                                                                                         As noted above, child support is the obligation of parents.  However, the term “parent” can  mean more that just biological or adoptive parents.  While biological and adoptive parents always pay full table child support, other people who have acted as a parent to a child can be on the hook for child support too.  That means that a step-parents can end up owing child support to his or her spouse’s ex.  Listen to this podcast that explains more.   This does not mean the step parent shares in his or her spouse’s child support obligation.  Instead, it means that step parents can acquire their own child support obligations for their spouses’ kids from prior relationships.  As explored in this video from a high-profile new story, acting as a parent to someone else’s kids can create a child support obligation - especially where a person does it with the best motivations.

A spouse is not directly responsible for the child support owed to the other spouse’s ex. However, that “innocent” spouse could end up sharing in that debt on separation after a marriage when his or her current spouse owes back child support to a former spouse. 

                                                                                                                                                                                                                                                   A spouse who acts like a parent to a partner’s children from a previous relationship can  also end up owing child support to that partner’s ex!

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You can get a lot more information about Ontario Family Law issues, including a comprehensive explanation of child support, spousal support, property division, and most other common family law issues by downloading this $9.99 Kindle eBook, Kobo eBook, or iBook for your iPad or iPhone or ordering it from Amazon as a paperback.  But to understand how the law works precisely in your situation, it is always best to speak to a good Family Law Lawyer.

To get the best advice, specific to your situation, you should speak to family lawyer.  Certified Specialist in Family Law, John Schuman, is known for his concern for children in separation and divorce and has won many child custody cases.  To contact John call 416-446-5847, email him, or fill out the form below. You can use the same form to comment on this page.   

Many thousands of people get family law assistance from this website everyday.  If you have found this page useful, please share it on your social network using the Facebook, Twitter, LinkedIn and Pinterest buttons at the bottom of the page.  Please comment on this page using the comments section at the bottom to share your thoughts on the best ways to resolve matters for your children after a separation. 


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