Common Law in Ontario: How Long, What Counts, and What You Get (2026)

Last updated: October 8, 2026

Common Law in Ontario: How Long, What Counts, and What You Get (2026)

Quick answer: There is no single rule for common law in Ontario. The answer depends on who is asking. For spousal support under Ontario's Family Law Act, unmarried partners count after three years of continuous cohabitation, or sooner in a relationship of some permanence if they are the parents of a child together. The CRA and IRCC use 12 months of living together. Property division and the matrimonial home rules apply only to married spouses, and a common-law partner does not inherit as a spouse when there is no will. There is no 6-month rule in Ontario family, tax, or immigration law, and no common-law certificate: people prove their status with a sworn statutory declaration and documents. A notary commissions that declaration; the agency or court that receives it decides what it means.

The question we hear most at our office in Orléans, in Ottawa, Ontario, is some version of "how long until we are common law?" It sounds like it should have one answer. It does not. Common law in Ontario is not a status you register or a date on a certificate. It is a set of definitions, each written for a different purpose. The Family Law Act has one for support. The Canada Revenue Agency has one for your tax return. IRCC has one for sponsorship. Pension plans, CPP, Ontario Works, and OSAP each have their own. The same couple can be common-law partners for their tax return and not yet for spousal support.

That is why the useful question is not "are we common law?" but "common law for what?" This guide answers it rule by rule. It covers how long each clock runs, what a common-law spouse is and is not entitled to in Ontario, what happens on separation or death, how people prove their status when there is no certificate, and what cohabitation agreements are. It also covers what a notary can do for you (commission declarations and affidavits, and witness agreement signatures) and when you need a family lawyer instead. It is general information, not legal advice; for your own situation, a lawyer is the right call.

Caption: Every common-law rule in Ontario starts from living together, but each law and agency sets its own clock.

Key Takeaways: Common Law in Ontario by Purpose

If you only read one thing, read the left column of that table. Find the purpose that brought you here, and use the rule beside it. The rest of this guide explains each row.

What "Common Law" Means in Ontario

In Ontario, a common-law relationship is two people who live together in a marriage-like (conjugal) relationship without being married. That is the everyday meaning. In law, it matters only when a statute, agency, or plan uses it, and each one writes its own definition.

Three points cause most of the confusion.

Common-law partners are not married. Ontario has no "common-law marriage." However long you live together, you do not become married in law. That is why the parts of the Family Law Act that deal with dividing property and the matrimonial home do not apply to you: they define a spouse as two people who are married to each other.

There is no registration. Ontario has no registry for common-law relationships and issues no common-law certificate. Your status is a conclusion someone draws from facts: when you started living together, whether you still do, whether you have a child together, and how you share your lives. When an agency needs proof, it asks you to swear to those facts and to back them up with documents.

Different laws, different clocks. The Family Law Act uses three years for support. The CRA and IRCC use 12 months. CPP uses one year. Social assistance can look at three months. None of them is "the" rule. Each answers a different question, and you can meet one definition while missing another.

The words also vary. Ontario's Family Law Act uses "spouse" for unmarried partners in its support part. Federal agencies say "common-law partner." In everyday speech, people say "common-law spouse." They all point at the same kind of relationship, measured against different rules.

How Long Is Common Law in Ontario?

The honest answer is: as long as the rule you are dealing with says. Here are the clocks people run into most, from longest to shortest.

Three years: spousal support and Ontario pensions

Section 29 of the Family Law Act defines "spouse" for the support part of the Act (Part III). It includes two people who are not married to each other and have cohabited continuously for at least three years, or who are in a relationship of some permanence and are the parents of a child together. Ontario's Pension Benefits Act uses a similar test for workplace pension plans.

So for spousal support between partners, the clock is three years of living together without a break, or less if you have a child together in a lasting relationship. The word "continuously" matters. If you have separated and reconciled, or lived apart for work, how that affects the count is a question for a family lawyer.

Twelve months: tax, benefits, and immigration

The Canada Revenue Agency treats someone as your common-law partner if you live together in a conjugal relationship and you have lived together for at least 12 continuous months, or they are the parent of your child by birth or adoption, or in certain custody situations involving your child. That definition decides how you file your tax return and how federal benefits and credits are calculated.

IRCC uses at least 12 consecutive months of living together in a conjugal relationship for common-law sponsorship and for listing a partner on an application. IRCC asks for proof, often including the IMM 5409 Statutory Declaration of Common-Law Union, which both partners sign. Our guide to the common-law statutory declaration for IRCC sponsorship covers that form in detail.

One year: the CPP survivor's pension

The Canada Pension Plan survivor's pension can go to a common-law partner who had lived with the contributor in a conjugal relationship for at least one year at the time of death.

Three months: Ontario Works and ODSP

Ontario's social assistance programs look at households, not just couples who meet the three-year test. Ontario Works and the Ontario Disability Support Program can assess two people as spouses once they have lived together for three months or more, using their own tests set out in the program directives. If you receive social assistance and someone moves in, tell your caseworker and ask how the rule applies to you.

The 6-month myth

You will see "six months" repeated online as the Ontario rule. We found no such rule in the Family Law Act, the CRA's definition, or IRCC's. It may come from a private source: a landlord's form, an employer's benefits plan, or an insurance policy can define a partner in its own words. If a form asks whether you are common law, look for the definition on the form or ask the organization that sent it. Answer for their definition, not the one you read on a forum.

OSAP and other programs

OSAP applications ask about marital status and use their own definition, which can differ between programs and years. Read the definition on the current application before you answer, and if OSAP asks for an affidavit, see our guide to the OSAP affidavit online.

What Is a Common-Law Spouse Entitled To in Ontario?

This is where the gap between married and unmarried couples is widest, and where the stakes are highest. The summary below is general; your entitlements depend on your facts, and a family lawyer is the right person to apply the rules to them.

Spousal support

A common-law partner who meets the section 29 definition (three years, or a relationship of some permanence and a child) can ask for spousal support under the Family Law Act, the same part of the Act that applies to married spouses. Meeting the definition does not mean support is owed. Whether support is payable, how much, and for how long depend on the relationship and each partner's circumstances.

Ontario's Limitations Act, 2002 says there is no limitation period for a proceeding to obtain support under the Family Law Act. That does not make timing unimportant. Evidence fades and circumstances change, so if support is in question, talk to a lawyer early.

Property and the family home

This is the biggest difference. The Family Law Act's equalization of net family property (Part I) and its matrimonial home rights (Part II) apply to married spouses only. For common-law partners, property generally belongs to the person who owns it. If the house is in one partner's name, the other partner does not get half by default, however long they lived there.

That is not the end of the story. In Kerr v. Baranow (2011), the Supreme Court of Canada explained how an unmarried partner can claim a share of property or wealth through the courts, for example by showing unjust enrichment, sometimes in a relationship that worked as a joint family venture. These claims are fact-specific and can be expensive to prove. A cohabitation agreement, signed while things are good, is how many couples avoid having to make them.

Children

Children's rights do not depend on whether their parents married. Child support and parenting arrangements for children of unmarried parents are dealt with under Ontario law, including the Family Law Act and the Children's Law Reform Act. If you are separating and have children, a family lawyer or a family law service can explain the process.

When a partner dies

If your partner dies without a will, Ontario's intestacy rules in the Succession Law Reform Act give the estate to a married spouse and relatives. A common-law partner does not inherit as a spouse, however long the relationship lasted.

A surviving partner is not always left with nothing:

• If you depended on your partner, you may be able to apply for dependant support from the estate under Part V of the Succession Law Reform Act, which uses the Family Law Act's section 29 definition.
• A workplace pension under Ontario's Pension Benefits Act may provide a survivor benefit to a partner who meets its definition.
• The CPP survivor's pension may be available after one year of living together.
• Beneficiary designations on life insurance, RRSPs, or TFSAs, and gifts in a will, apply as written.

These are estate questions, and an estates lawyer is the person to ask. The simplest protection is for each partner to have a will. Our guide to wills and estates notary services explains where a notary fits.

Common-Law Separation in Ontario

Ending a common-law relationship does not involve a court by default. Divorce applies only to married couples. Common-law partners separate by living separate and apart.

What separation does involve is sorting out the practical consequences: who stays in the home, how shared accounts and debts are divided, support, and arrangements for children. Many couples record what they agree in a separation agreement. Under the Family Law Act, a separation agreement is a domestic contract, and section 55 says a domestic contract is unenforceable unless it is in writing, signed by the parties, and witnessed.

A separation agreement is a legal document with long-term consequences. Each partner should get advice from their own lawyer before signing. A notary can witness the signatures; a notary cannot tell you whether the terms are fair. If you are not sure where that line is, our piece on notary vs lawyer in Ontario explains it.

Some agencies also ask for a sworn statement of the separation date, for example to update your marital status for tax and benefits, or for an immigration file. A statutory declaration of separation is the usual document. We have a free statutory declaration of separation template you can adapt, and we commission it at the appointment.

Caption: There is no common-law certificate in Ontario. People prove the relationship with a sworn declaration and documents that show a shared home.

How to Prove Common-Law Status in Ontario

Because there is no certificate, proof always comes in two parts: a sworn statement of the facts, and documents that back it up.

The sworn statement is usually a statutory declaration. You declare, solemnly and in front of a commissioner or notary, when you started living together, where, and that you still live together (or when you separated). A false declaration carries real consequences under the Criminal Code, which is why agencies accept it as evidence.

The documents show a shared life at a shared address. The ones agencies most often ask for include:

• a joint lease or a mortgage or property deed in both names;
• utility, phone, or internet bills at the same address;
• bank statements for a joint account, or separate statements showing the same address;
• government ID or CRA notices showing the same address;
• insurance policies naming each other as beneficiary or covering the same home;
• mail addressed to each of you at the same address over time.

Who is asking decides which form you use:

If the organization has its own form, use it. If it simply asks for "a statutory declaration," our free statutory declaration of common-law union template is a starting point, and the IMM 5409 template guide and OSAP affidavit of common-law status cover the two most common agency forms. For IRCC files, our guide to relationship proof for spousal sponsorship goes further into the evidence.

Cohabitation Agreements

A cohabitation agreement is a contract between two people who live together, or plan to, and are not married. Section 53 of the Family Law Act allows it. It can deal with matters such as who owns what, how property is divided if you separate, and support. Ontario law limits what such an agreement can say about children, and a lawyer can explain those limits.

Three things are worth knowing before you start.

It must be in writing, signed, and witnessed. Section 55 of the Family Law Act applies to every domestic contract. An agreement that skips those steps can be unenforceable.

If you marry, it becomes a marriage contract. Section 53 says that if the partners to a cohabitation agreement marry each other, the agreement is treated as a marriage contract. Many couples sign one with that in mind.

It should be drafted or reviewed by a lawyer. A cohabitation agreement changes what each of you would otherwise be entitled to. Each partner should get their own legal advice before signing. Our free cohabitation agreement template shows what one typically covers, but it is a starting point for a conversation with a lawyer, not a substitute for one.

Once the agreement is final, we can witness the signatures. Our practice for cohabitation and separation agreements is an in-person signing on a mobile visit, with two adult witnesses present.

What a Notary Can and Cannot Do

For common-law paperwork, a notary's role is narrow, and it is the same role whatever form you bring.

A notary can:

• commission a statutory declaration of common-law union, or of separation, for an employer, insurer, pension plan, or other organization;
• commission IRCC's IMM 5409 with both partners present, in person or over video;
• commission an OSAP affidavit of marital status;
• witness the signatures on a cohabitation agreement or separation agreement that a lawyer has drafted or reviewed;
• certify true copies of supporting documents, such as a lease or ID, when an organization asks for certified copies (in person, with the originals).

In each case, the notary identifies each person from government photo ID, takes the solemn declaration or watches the signature, completes the jurat or witness block, and applies the seal.

A notary cannot:

• decide whether you are common law. The organization, agency, or court that receives your declaration decides that, under its own definition;
• tell you what you are entitled to on separation or death, or whether to claim support or property;
• draft, review, or negotiate a cohabitation or separation agreement, or tell you whether its terms are fair;
• give independent legal advice before you sign an agreement;
• give immigration advice about a sponsorship or application;
• fill in or change the substance of your declaration. The facts are yours; the seal is ours.

When to Call a Family Lawyer Instead

A notary appointment is the right step when you know the facts, have the form, and need it commissioned or witnessed. Call a family lawyer first when:

• you are separating and there is a home, savings, a business, debt, or children to sort out;
• you think you may have a claim for spousal support, or your partner is asking you for support;
• you contributed to property in your partner's name and want to know whether you have a claim;
• your partner has died without a will, or you depended on them and are not provided for;
• you want a cohabitation agreement or separation agreement drafted, or need independent legal advice before signing one;
• you and your partner disagree about when you started living together or when you separated;
• an IRCC file is complex, in which case a lawyer or a licensed immigration consultant is the right adviser.

If cost is a concern, the Law Society of Ontario runs a referral service that can connect you with a lawyer, and Steps to Justice publishes plain-language family law information for Ontario.

Caption: A lawyer drafts and explains a cohabitation or separation agreement. A notary can witness the signatures once the terms are final.

Five Ottawa Scenarios

These are illustrative situations of the kind we hear about at the office. Names and details are invented; the questions are real.

A Kanata couple sponsoring a partner after 14 months. They moved in together a little over a year ago and want to start a common-law sponsorship. For IRCC and the CRA, they are past the 12-month line. For spousal support under the Family Law Act, they are not yet at three years, which does not matter for the immigration file. They book an IMM 5409 appointment, both attend with photo ID, and the declaration is commissioned. IRCC decides the application.

An Orléans couple separating after four years. The house is in one partner's name, and the other partner paid half the mortgage for three years. Neither knows what that means. This is a lawyer's question first: the property rules for married spouses do not apply, and any claim depends on the facts. Once each has had advice and they sign a separation agreement, we witness the signatures.

A Barrhaven couple asked about "common law" at seven months. A benefits enrolment form asks whether they are common-law partners. They had read that Ontario uses six months. The form defines a partner as someone you have lived with for 12 months, so the answer is no for now. The definition on the form is the one that counts.

A uOttawa student and OSAP. A student who lives with a partner is asked by OSAP to swear an affidavit about marital status. OSAP's own definition decides what to declare. Once the student has read it and completed the form, we commission the affidavit.

A partner in the Glebe after a death. A long-term partner died without a will. The surviving partner assumed the estate would come to them, and learned it does not under the intestacy rules. They speak to an estates lawyer about dependant support, the pension survivor benefit, and CPP. If the lawyer prepares affidavits for the estate file, we can commission them.

The pattern is the same each time. The first question is which rule applies. The second is whether the facts meet it. The notary's part comes after both are answered.

What to Bring to Your Appointment

The checklist depends on what you are signing.

For a statutory declaration (common-law union, separation, IMM 5409, OSAP):

• The form, completed but unsigned. Use the organization's own form if it has one. Leave the signature lines blank; you sign in front of the notary.
• Government-issued photo ID for each person signing, current and not expired. A foreign partner can use their passport.
• Both partners, when the form is a joint declaration such as IMM 5409.
• The key dates and addresses, so you can check them against the form before you swear to them: when you started living together, each address since, and any separation date.
• Any supporting documents the form says to attach, as exhibits if required.

For witnessing a cohabitation or separation agreement:

• The final agreement, unsigned, after each partner has had legal advice.
• Both partners, each with current government photo ID.
• A quiet place for the signing, since our practice is a mobile visit to your home or office.

For certified true copies: the original documents. A copy of a copy cannot be certified.

Pricing and Booking

Prices are before HST. Book through the contact page or call (613) 434-5555, and tell us which form you have. A short call confirms whether the appointment can be online, at the office, or on a mobile visit.

Frequently Asked Questions

How long do you have to live together to be common law in Ontario?

It depends on who is asking. For spousal support under Ontario's Family Law Act, it is three years of continuous cohabitation, or a relationship of some permanence if you are the parents of a child together. The Canada Revenue Agency and IRCC use 12 months of living together. The CPP survivor's pension uses one year. Check the definition used by the law, agency, or plan that is asking.

Is there a 6-month common-law rule in Ontario?

Not in Ontario family law, tax law, or immigration law. The Family Law Act uses three years (or a child), and the CRA and IRCC use 12 months. Ontario Works and ODSP can start treating people as spouses after three months of living together, using their own test. A private plan, such as an employer's benefits plan, may set its own rule, so read the plan's wording.

Do common-law partners split property 50/50 in Ontario?

Not automatically. The property-division rules in Part I of the Family Law Act, and the matrimonial home rules in Part II, apply to married spouses. A common-law partner who contributed to property in the other partner's name may have a claim through the courts, such as unjust enrichment, as the Supreme Court of Canada explained in Kerr v. Baranow. Those claims depend on the facts, so speak to a family lawyer.

Does a common-law partner inherit if there is no will in Ontario?

Not as a spouse. Ontario's intestacy rules in the Succession Law Reform Act use the married-spouse definition. A common-law partner who depended on the deceased may be able to apply for dependant support from the estate under Part V of the same Act, and pension or CPP survivor rules may apply separately. An estates lawyer can explain the options.

Is there a common-law certificate in Ontario?

No. Ontario has no registry or certificate for common-law relationships. People usually prove their status with a sworn statutory declaration plus documents that show a shared address, such as a joint lease, bills, or bank statements. Some agencies have their own forms, like IRCC's IMM 5409.

Can a notary declare us common law?

No. A notary commissions your statutory declaration: we identify you, take your solemn declaration that the facts are true, watch you sign, and apply the seal. Whether you count as common-law partners is decided by the agency, plan, or court that receives the declaration, under its own definition.

Does a cohabitation agreement need to be notarized in Ontario?

The Family Law Act says a domestic contract, including a cohabitation agreement, must be in writing, signed by the parties, and witnessed. It does not say the agreement must be notarized. Many couples have a notary witness the signatures. A lawyer should draft or review the agreement; a notary does not advise on its terms.

Do we need a divorce to end a common-law relationship in Ontario?

No. Divorce applies to married couples. Common-law partners separate by living separate and apart. Many couples record the terms in a separation agreement, which is a domestic contract that must be in writing, signed, and witnessed. Some agencies also ask for a sworn declaration of the separation date.

Final Recommendation

Start with the purpose. Find the row in the table at the top that matches why you are asking (tax, immigration, support, property, an estate, a benefits form) and use that rule, not the one a friend or a forum mentioned. If a form asks whether you are common law, answer for the form's own definition.

If you are proving a relationship, gather the documents that show a shared address over time, use the organization's own form if it has one, and have the declaration commissioned. If you are separating, buying property together, or dealing with a partner's estate, see a family or estates lawyer before you sign anything. The notary's part is the last step: making sure the declaration or agreement you have settled on is sworn or signed and sealed correctly.

Book Your Appointment

• Service: Statutory Declarations, from $24.95 per seal + HST, for common-law union and separation declarations and IMM 5409.
• Phone: (613) 434-5555. Call to confirm the form and whether your appointment can be online.
• Online: Book or send a question through the contact page.
• In person: Our Orléans office, 8056 Jeanne d'Arc Blvd N, Ottawa, Ontario, or a mobile visit for agreements.

Sources

• Family Law Act, R.S.O. 1990, c. F.3 — ss. 1, 29, 53, 55 (Ontario e-Laws)
• Succession Law Reform Act, R.S.O. 1990, c. S.26 — s. 1 and Part V (Ontario e-Laws)
• Limitations Act, 2002 — s. 16 (Ontario e-Laws)
• Pension Benefits Act, R.S.O. 1990, c. P.8 (Ontario e-Laws)
• Children's Law Reform Act, R.S.O. 1990, c. C.12 (Ontario e-Laws)
• Kerr v. Baranow, 2011 SCC 10 (Supreme Court of Canada)
• Canada Revenue Agency — Marital status
• IRCC Help Centre — What is a common-law partner?
• IRCC — IMM 5409 Statutory Declaration of Common-Law Union
• Government of Canada — CPP survivor's pension
• Ontario Works policy directive 3.3 — Co-residency
• ODSP income support directive 2.3 — Spouse
• Ontario — Guide for newly appointed commissioners for taking affidavits