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Ontario Separation Agreement Checklist: Items to Settle Before Signing

Work through a practical Ontario separation agreement checklist covering disclosure, support, parenting, property, pensions and signing requirements.

Family Law5 min readTSLBy the Treadstone Law Team · OntarioUpdated November 13, 2026
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Key takeaways
  • A separation agreement can cover support, parenting, property and pensions, and it is hard to change or set aside once signed.
  • A court may set aside an agreement if a party did not disclose significant assets or debts, or did not understand its nature or consequences, but that alone is not enough, because the court then decides whether to use its discretion and fairness is one consideration.
  • To be enforceable, the agreement must be in writing, signed by both of you and witnessed.

Separating usually means making a lot of decisions at once: who pays what, where the children live, what happens to the home and the pensions. A separation agreement is where those decisions get written down, and it can be hard to undo later.

This checklist walks through the main items to settle before you sign. It explains how Ontario law generally treats each one, so you know what to ask and where a lawyer's advice may matter most.

Start with the basics and full disclosure

In Ontario, two people who lived together and are now living separate and apart may make an agreement setting out their rights and obligations, whether they were married or not. A separation agreement is one kind of domestic contract under the Family Law Act.

Disclosure comes first. In family court, financial disclosure means giving the other side information and documents about your income, expenses, assets and debts. A court may set aside an agreement if a party failed to disclose significant assets or significant debts that existed when the contract was made. The spouse who holds the assets is responsible for disclosing and valuing them.

Support for you and for the children

Child support for children under the age of majority is presumed to be the table amount, based on the number of children and the payor's income, plus any special or extraordinary expenses. Those extra expenses can include child care, certain medical and dental costs, school expenses and extracurricular activities. They are shared in proportion to each spouse's income, after deducting any contribution from the child.

Where each spouse has at least 40% of parenting time over a year, the amount is worked out differently, by looking at both table amounts and the costs of shared parenting. A court may disregard a child support term that is unreasonable having regard to the child support guidelines.

Spousal support is not automatic. You may be entitled if you were married, lived together as a couple for at least three years, or were in a relationship of some permanence and had a child together. Lawyers and judges often use the Spousal Support Advisory Guidelines, which are not law, to estimate the amount, and an agreement may include a review date.

Parenting arrangements

Decision-making responsibility is the right to make significant decisions about a child's life and well-being, and parenting time is the time a child spends in a parent's care. A parenting plan can set out each parent's time and who makes major decisions. An informal arrangement can be difficult to enforce, while you can ask the court to enforce parenting arrangements made in a separation agreement.

Think about moves too. A person with parenting time or decision-making responsibility who intends a relocation must notify others with decision-making responsibility, parenting time or contact at least 60 days before the expected move date. For divorcing spouses, the Divorce Act sets the same 60-day rule, but the court may, on application, waive or modify the notice requirements, including where there is a risk of family violence. A court can also disregard a parenting term in a domestic contract if doing so is in the child's best interests.

Home, property and pensions

For married spouses, property is generally divided through equalization: each spouse's net family property is worked out, and the spouse with the larger amount pays the other an equalization payment. Spouses must share the full value of the family home, equally unless they agree to a different split. In a separation agreement, spouses can divide property any way they agree.

Unmarried couples are not covered by equalization and are not legally required to split property acquired while living together. A partner who contributed to property the other owns may have a claim, and the separation agreement is where such claims are settled.

For pensions, ask the plan administrator about value. A domestic contract cannot entitle the eligible spouse to more than 50% of the imputed value of the member's pension. Canada Pension Plan credits earned while living together can also be split after separation.

Signing and what to do next

A separation agreement must be in writing, signed by the parties and witnessed, or it may be unenforceable. You do not need a lawyer to make one, but legal advice before signing is a good idea because it can be difficult to get a court to set an agreement aside. Each person should understand the terms and not be pressured to sign.

If support is part of the deal, the agreement can be filed with the court and registered with the Family Responsibility Office for enforcement. Confirm the current filing steps with a lawyer.

Frequently asked questions

Do I need a lawyer to make a separation agreement in Ontario?

No, you do not need a lawyer to make one. Legal advice before signing is still a good idea, because it can be difficult to get a court to set an agreement aside.

Can a separation agreement be changed later?

Support terms can be changed by an updated agreement or by a court order if circumstances change, such as a change in income or remarriage. Any amending agreement must also be in writing, signed and witnessed.

What happens if my spouse hid assets?

A court may set aside an agreement, or part of it, if a party failed to disclose significant assets or debts that existed when it was made. Even then, the court decides whether it is appropriate to use its discretion, and fairness is a consideration.

Does the checklist change if we are not married?

Yes, in places. Equalization does not apply to unmarried couples, so property claims often turn on who bought or contributed to what. Spousal support depends on your situation, so a lawyer can confirm it.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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