Common-Law Separation Agreement:

Guidance for Unmarried Couples

Many people in Ontario separate after a long-term relationship without ever marrying. In that situation, you may still need clear, enforceable terms about parenting, support, and finances. A common-law separation agreement—also searched as an unmarried separation agreement, a separation agreement not married, or a separation agreement for unmarried couples—is often the most practical way to document what has been agreed and reduce future disputes.

Important disclaimer (general information only): This article provides general information about common-law separation agreements in Ontario. It is not legal advice. Outcomes depend on individual facts, the wording of any agreement, and the circumstances of each relationship. For advice about your situation, contact Aaries Family Law.

 

What is a common-law separation agreement?

A common-law separation agreement is a written contract between unmarried partners who have separated (or are separating). It can set out:

• Parenting arrangements (decision-making responsibilities and parenting time)
• Child support
• Spousal support (where applicable)
• Property and debt responsibilities
• Practical terms (insurance, disclosure, dispute resolution, timelines for implementation)

People may use different phrases—cohabitation separation agreement, living together separation agreement, partner separation agreement, relationship separation agreement, or couple separation agreement—but the intent is usually the same: to create a clear written record of the terms you both intend to follow after the relationship ends.

A well-drafted agreement can help avoid misunderstandings and reduce the risk of later conflict about what was promised, what was paid, or what was supposed to happen with shared property and debts.

Does “common-law” status matter in Ontario?

Common-law can be a practical label, but it does not always mean the same thing in every legal context. In Ontario, different rules may apply depending on the issue (for example, child-related issues, support, or property-related claims).

In general terms, a separation agreement can be useful for unmarried partners regardless of whether they meet a specific legal definition of “common-law” for a particular purpose. The key is that you shared a relationship and now need to define your rights and obligations moving forward.

Because status and entitlements can be fact-specific, obtaining legal advice early is often prudent—especially where there are children, significant assets, a jointly owned home, or uneven financial circumstances.

 

Key differences between married and unmarried separation in Ontario

Many disputes arise because unmarried partners assume separation works the same way as divorce. In Ontario, the legal analysis often differs between married spouses and unmarried partners, particularly around property.

Property and debts: why common-law separation can be more fact-driven

For unmarried partners, property outcomes are often more dependent on:

• Ownership/title (whose name an asset is in)
• Contributions (financial and, sometimes, non-financial)
• Any written agreements made during the relationship
• The overall history of how assets and debts were managed

This is why a common-law separation agreement is often especially valuable: it can create clarity where the default rules do not automatically produce a straightforward “split.”

Common practical issues include:

• A home owned in one partner’s name, but paid for jointly
• Joint debts that remain in both names even after separation
• Shared purchases where receipts and ownership are unclear
• Disagreement about reimbursement for renovations or down payments
• Support: child support and spousal support

Child support may be relevant whenever parents separate, regardless of marital status.

Spousal support may also be relevant for unmarried partners in some circumstances, depending on the facts of the relationship (length of cohabitation, roles during the relationship, financial impact of separation, and other considerations).

A separation agreement can set out support terms clearly, but support clauses should be drafted carefully and typically require meaningful financial disclosure to reduce enforceability disputes.

Parenting: decision-making responsibilities and parenting time

Parenting arrangements are not limited to married parents. If you have children, a separation agreement can document a parenting plan, including:

• Parenting time schedule
• Decision-making process
• Holidays, vacations, and exchanges
• Communication expectations
• Dispute-resolution steps
  Clarity helps protect children’s routine and reduces conflict.

 

When is a common-law separation agreement useful?

A common-law separation agreement is often beneficial when:

• You have children and need a stable parenting plan
• One partner earned more income or the relationship created financial dependence
• You lived together and share significant expenses or debts
• You purchased property together or one partner contributed to the other’s property
• You want a clear plan for moving out, paying bills, and handling shared accounts
• You want to reduce uncertainty before starting a new relationship, buying property, or making major financial decisions

Even when the separation is amicable, a written agreement can prevent future disputes caused by unclear expectations.

 

What should a separation agreement for unmarried couples include?

A well-drafted agreement is tailored to the family’s facts. Common sections include parenting, support, and financial terms, along with practical implementation details.

Parenting arrangements

If you have children, parenting terms often address:

• Weekly schedule and exchange logistics
• Holidays, school breaks, and vacations
• Decision-making responsibilities (education, health, activities)
• Communication guidelines
• Travel and notice provisions
• A process for resolving disagreements (often negotiation and/or mediation steps)

People sometimes search for a “separation and custody agreement” or “separation custody agreement.” In practice, that usually means a separation agreement with a detailed parenting plan.

Child support

Child support provisions often include:

• Amount, payment method, and payment date
• How income information will be exchanged and updated
• How additional child-related expenses will be handled (where relevant)
• Benefit coverage and uninsured expenses (where applicable)

Because child support is closely connected to income and children’s needs, support terms should be drafted with care and supported by accurate disclosure.

Spousal support (where applicable)

Spousal support provisions may address:

• Whether support will be paid
• Amount and duration (or a framework for determining them)
• Review dates or triggers
• Disclosure obligations and income updates
• Tax-related considerations (where relevant and fact-dependent)

Where a party proposes a release of spousal support, the risks should be assessed carefully, typically with independent legal advice and meaningful disclosure.

Property and debts (including shared accounts)

Property and debt terms for unmarried couples often focus on practical realities and clear commitments, such as:

• Who keeps which assets (vehicles, furniture, accounts)
• How jointly owned property will be dealt with
• Reimbursement arrangements (if agreed) for specific contributions
• Responsibility for joint debts and a plan to reduce ongoing joint liability
• Timelines for closing accounts, refinancing, transferring, or selling assets
• Clear “implementation steps” are often as important as the final outcome. Many disputes arise because the agreement states the intention (for example, “we will sell the home”) but does not specify deadlines, listing steps, or what happens if one party does not cooperate.
• Practical clauses that reduce future disputes

Depending on the family’s needs, agreements often include:

• Disclosure confirmations
• Deadlines and document exchange obligations
• Insurance provisions
• Dispute-resolution steps (for example, negotiation then mediation before court)
• Confidentiality clauses (where appropriate)

 

Financial disclosure: a foundation for enforceable support and fair settlement

A separation agreement is more likely to be durable when it is built on meaningful financial disclosure. Disclosure helps ensure that support and financial terms are informed, realistic, and defensible.

Depending on the issues, disclosure often includes:

• Recent income tax returns and notices of assessment/reassessment
• Current proof of income (employment or self-employment)
• Bank and investment statements
• Debt statements (credit cards, loans, lines of credit)
• Mortgage statements and property details
• Pension and benefit information (where relevant)
• Business financial information (where relevant)

Where disclosure is incomplete, it can be difficult to negotiate stable support or property terms, and it can increase later conflict about fairness and enforceability.

 

When is a common-law separation agreement legally binding?

A separation agreement is generally intended to be a binding contract. Enforceability often depends on both:

• The process used to negotiate and sign,
• The clarity and completeness of the terms, and
• Signing and witnessing

Separation agreements are typically:

• In writing
• Signed by both parties
• Dated
• Witnessed
• Independent legal advice

Independent legal advice (each party obtaining advice from their own lawyer) is not always strictly required in every situation, but it is commonly recommended because it can:

• Help each person understand the terms and consequences
• Reduce later claims of misunderstanding or pressure
• Identify missing clauses and drafting issues
• Strengthen the overall reliability and enforceability of the agreement
• Notarization and commissioning (common question)

Some people ask whether they need a notary for a “notarized separation agreement.” In many circumstances, notarization is not required for a separation agreement to be enforceable. However, parties sometimes choose an extra formality step depending on the circumstances and execution logistics. The appropriate approach depends on the facts and the specific document being signed.

Situations that can increase enforceability risk (general)

While every case is fact-specific, enforceability disputes more often arise when there are allegations of:

• Incomplete or misleading financial disclosure
• Significant pressure to sign without review time
• Lack of understanding of the terms and consequences
• Ambiguous drafting that makes obligations unclear
  This is one reason legal advice and careful drafting are often important, even for amicable separations.

 

Do you need a lawyer for a common-law separation agreement in Ontario?

Many people attempt to resolve matters privately, but legal guidance can significantly reduce risk—particularly where property and spousal support are involved.

Aaries Family Law can assist with:

• Advising on likely issues and risk areas for unmarried couples
• Structuring financial disclosure and documentation
• Drafting clear terms and implementation steps
• Negotiating to resolve disputes efficiently
• Reviewing an agreement for enforceability and missing clauses
• Contact Aaries Family Law
  If you are separating and want a common-law separation agreement drafted or reviewed, Aaries Family Law can help you move forward with clear, durable terms.

 

Living together after separation: “in-home” separation considerations

Some couples separate but continue living under the same roof for financial or parenting reasons. In those situations, a living together separation agreement (or “in-home separation” arrangement) may help establish clarity about:

• Household expenses and financial boundaries
• Parenting routines and responsibilities
• Use of shared spaces
• Expectations about new relationships and privacy
• Communication rules and dispute-resolution steps
• Timelines for transitioning to separate residences (if planned)

Agreements in this context often require particularly careful drafting to reduce misunderstandings and protect children’s stability.

 

Common mistakes in unmarried separation agreements

Even cooperative couples can create future disputes if key issues are not addressed clearly. Common mistakes include:

• Assuming property will automatically be divided equally
  Unmarried property outcomes can be highly fact-dependent. Clear written terms can prevent incorrect assumptions from becoming conflict later.
• Failing to address joint debts and ongoing liability
  Even if one person agrees to pay a joint debt, lenders may still treat both parties as responsible if both names remain on the account.
• Vague parenting terms
  Words like “reasonable parenting time” often lead to conflict. Clear schedules and holiday plans usually prevent disputes.
• Support terms without disclosure and update mechanisms
  Support clauses should typically address how income information will be exchanged and updated.
• Missing implementation steps for property transfers
  If a home is being sold or bought out, timelines, valuation steps, and documentation responsibilities should be addressed.
• Using generic templates that do not fit the family’s facts
  Templates are often not designed for Ontario-specific realities and may omit essential clauses.

 

Changing a common-law separation agreement later

Circumstances can change. Income may change, children’s needs may evolve, and practical arrangements may become unworkable. When both parties agree, changes are often documented through:

• A written amendment or addendum, signed and witnessed properly, or
• A new agreement that replaces the original terms in whole or in part
  If one party wants changes and the other does not, the options depend on the facts and the nature of the term at issue. Legal advice is recommended before taking steps that may escalate conflict.

 

Next steps: how Aaries Family Law can help

A common-law separation agreement can create stability and protect your financial and parenting interests—especially when it is built on meaningful disclosure, clear drafting, and practical implementation steps.

Aaries Family Law assists clients across Ontario with:

• Drafting and negotiating common-law/unmarried separation agreements
• Reviewing agreements for clarity and enforceability risk
• Parenting plans, support terms, and financial settlements
• Amendments when circumstances change

 

Frequently Asked Questions (Common-Law / Unmarried Separation Agreements)

1. Can unmarried couples make a separation agreement in Ontario?

• Yes. Unmarried couples commonly use separation agreements to document parenting, support, and financial terms after separation.

2. Is a “common-law separation agreement” different from a separation agreement for married spouses?

• It can be. The agreement format may be similar, but the underlying property analysis and settlement considerations for unmarried couples are often more fact-driven.

3. Does child support apply if we were not married?

• Child support may apply based on parentage and the child’s needs, regardless of whether the parents were married.

4. Can spousal support apply if we were common-law?

• Spousal support may be relevant for unmarried partners in some circumstances. Whether it applies depends on the facts of the relationship and financial impact of separation.

5. If my name is not on the home title, do I have any claim?

• This depends on the facts, including contributions and the history of the relationship. Legal advice is strongly recommended where ownership and contributions are disputed.

6. Is a common-law separation agreement legally binding?

• It is generally intended to be binding if it is properly drafted, signed, and supported by a fair process and meaningful disclosure. Enforceability is fact-specific.

7. Do we need independent legal advice?

• Independent legal advice is commonly recommended because it helps ensure understanding and reduces later disputes about fairness or pressure.

8. Do we need to notarize the agreement?

• Notarization is not typically required for enforceability, though it may be used in some situations depending on execution logistics.

9. What if my partner refuses to sign?

• You may still pursue structured negotiation, mediation, or other steps depending on the issues and urgency. Legal advice can help determine practical options.

10. Can we change the agreement later?

• Often yes, by a properly documented amendment or replacement agreement, depending on the circumstances and the terms involved.