Separation Agreements in Ontario: What to Include

When a relationship ends, one of the most important things you can do is put your arrangements in writing. A separation agreement is a legally binding contract between two former spouses or partners that sets out how you will handle property, finances, and — where children are involved — their care. Done right, it gives both parties certainty and can save years of ongoing conflict.

This article explains what a separation agreement in Ontario should cover, what makes one enforceable, and where people commonly run into problems.

What Is a Separation Agreement?

A separation agreement is a type of domestic contract recognized under Ontario's Family Law Act. It can be used by married spouses, common-law partners, or any two people who were in a conjugal relationship. It does not require a court application — you and your former partner negotiate and sign it.

Once signed, it is legally binding and can be filed with a court to make it enforceable the same way a court order is enforceable (including through the Family Responsibility Office for support payments).

You do not need to be divorced before signing a separation agreement. In fact, most couples sign the agreement while they are legally still married — the agreement governs their separation, and the divorce (if they choose to pursue it) can come later.

What a Separation Agreement Should Cover

A comprehensive separation agreement addresses every significant issue arising from the relationship. Leaving something out can mean uncertainty or conflict later. The main topics are:

Property Division

The agreement should set out how all significant assets and debts will be divided. This includes:

• The matrimonial home (who stays, who buys out the other, how sale proceeds are divided)
• Investment accounts, savings, and bank accounts
• Retirement savings and pension entitlements
• Vehicles
• Debts (mortgage, line of credit, credit cards) and who assumes each one
• Any business interests

For married spouses, the agreement effectively replaces the equalization process the Family Law Act would otherwise impose. The parties can agree to equalization, modify it, or opt out of it entirely — as long as the agreement meets the formal requirements.

Spousal Support

The agreement should address whether spousal support will be paid, and if so:

• The monthly amount
• The duration (fixed term, indefinite, or reviewable)
• What events will trigger a review or termination (e.g., the recipient obtaining employment, either party retiring)
• Whether it will be periodic (regular payments) or a lump sum

If support is expressly waived — meaning one party gives up their right to claim it — that should also be clearly stated. A waiver of support may be appropriate in some situations, but both parties should understand what they are giving up.

Decision-Making Responsibility and Parenting Time

Where there are children, the agreement must address:

• Decision-making responsibility (formerly called custody): who makes major decisions about the children's education, health, religion, and extra-curricular activities — one parent alone or both jointly
• Parenting time (formerly called access): the schedule for when the children are with each parent, including holidays, birthdays, and summer vacations
• How communication between parents will happen and how disputes will be resolved

Courts retain jurisdiction to revisit parenting arrangements if circumstances change and it is in the child's best interests — even if the parties have agreed. An agreement that simply says "reasonable parenting time as agreed" is difficult to enforce and tends to generate ongoing conflict; detailed schedules work better.

Child Support

The agreement should set out child support in accordance with the Federal Child Support Guidelines — specifically the table amount based on the payor's income, plus a mechanism for sharing section 7 (special) expenses. The agreement should also provide for annual income disclosure and updating of child support when income changes materially.

Other Practical Issues

Depending on your situation, you may also want to address:

• Whether either party will remain on the other's extended health insurance and for how long
• How joint debts will be handled pending sale of the home
• Possession of personal property (furniture, household contents)
• Any ongoing financial obligations (for example, one party paying for the children's post-secondary education)

Financial Disclosure: The Foundation of Enforceability

Before a separation agreement is signed, both parties must provide full financial disclosure. This means exchanging documentation of all income, assets, and debts — typically through sworn financial statements, supported by income tax returns, bank statements, and other records.

Financial disclosure is not optional. If one party hides assets, understates income, or otherwise fails to disclose fully, the agreement can be set aside by a court later — even years later. Courts have been very willing to invalidate agreements where disclosure was incomplete or misleading. The agreement is only as solid as the disclosure behind it.

This is one of the reasons it is important to approach a separation agreement carefully, not just as a document to sign quickly and move on. Rushing past disclosure to get to the finish line creates a risk that the agreement will not hold.

Independent Legal Advice

Both parties should obtain independent legal advice (ILA) before signing a separation agreement. This means each person consults their own lawyer — not a shared lawyer, and not just one party having a lawyer while the other does not.

Having ILA does not guarantee an agreement is unassailable, but the absence of ILA is a major red flag that courts will consider if one party later seeks to set the agreement aside. A lawyer providing ILA typically signs a certificate confirming that they explained the nature and consequences of the agreement to their client, who appeared to understand and sign voluntarily.

ILA also protects you. Having a lawyer review the agreement before you sign is your chance to identify terms that are unfair, missing, or legally unenforceable — before it is too late to negotiate.

Formal Requirements

For a separation agreement to be valid under the Family Law Act:

• It must be in writing
• It must be signed by both parties
• Signatures must be witnessed

There is no requirement to have it notarized or filed with a court for it to be binding between the parties. Filing is only necessary if you want court-level enforcement (for example, enrolling support payments with the Family Responsibility Office).

When an Agreement Can Be Set Aside

A court can set aside or vary a separation agreement in limited circumstances:

• A party failed to disclose significant assets or debts
• A party did not understand the nature or consequences of the agreement
• One party exerted undue influence or there was duress
• The agreement is unconscionable (deeply, fundamentally unfair in a way that shocks the conscience)
• For parenting and child support terms: if the agreement no longer serves the children's best interests

Courts approach setting aside agreements with caution — they are reluctant to undermine settlements reached by adults with legal advice. But real abuses are taken seriously.

Frequently asked questions