The letter arrives months after the breakup. Sometimes years later.
It's from a lawyer. Your ex-partner's lawyer. And it says, in careful legal language, that you owe spousal support.
You were never married. You had a place together for a few years, sure — but a ring, a ceremony, a certificate? None of that. So this has to be some kind of mistake.
It is not a mistake.
This is the most expensive misconception in Ontario family law: that "not married" means "no obligations." And it catches people completely off guard, every single day.
Here's the reality. If you lived together for three or more years — or if you have a child together, with no time minimum at all — you may owe spousal support when the relationship ends. And here's the part that really gets people: the formula used to calculate it is exactly the same as for married couples.
Same SSAG formulas. Same Rule of 65 for indefinite support. Same income difference calculation. Same everything.
The one thing that's genuinely different from marriage is property division — common law couples don't have the same automatic splitting rules. But for support? You're treated essentially the same as if you'd said "I do" in front of a judge.
Every year, people walk out of long common law relationships believing they have no financial exposure. They start fresh. Then the letter arrives.
The Bottom Line
When you qualify: Lived together 3+ years, OR any time if you have a child together
Spousal support: Same rules as married couples (SSAG formulas)
Property division: NOT the same as married couples—no automatic 50/50 split
The gotcha: Many people think "not married = no obligations." They're wrong about support, right about property.
When Do You Qualify as Common Law?
Under Ontario's Family Law Act, you're in a common law relationship (called "spouse" in the Act) if:
Option 1: The 3-Year Rule
You've lived together continuously for at least 3 years.
This means actually living together as a couple—sharing a home, presenting yourselves as partners, the whole picture. Occasionally spending the night doesn't count. Living in the same apartment building doesn't count. It needs to be cohabitation in a conjugal relationship.
Option 2: The Child Rule
You live together in a relationship of some permanence and have a child together.
If you have a child together, there's no minimum time requirement. A couple who's been together for 6 months with a baby can qualify for spousal support. The child creates the connection.
Examples: Who Qualifies?
Couple A: Together 4 years, no kids, lived together the whole time. Qualify under the 3-year rule.
Couple B: Together 2 years, no kids, lived together the whole time. Don't qualify yet.
Couple C: Together 1 year, have a baby together, lived together since the baby was born. Qualify under the child rule.
Couple D: Together 5 years, lived together for 2 of them, no kids. Don't qualify—only 2 years of cohabitation.
The "continuous" requirement: Breaks in cohabitation can affect whether you hit 3 years. If you lived together for 2 years, broke up for 6 months, then got back together for another year, courts will look at whether the relationship truly ended during the break or whether you were just "on a break." Short separations during an ongoing relationship usually don't reset the clock.
How Courts Determine Cohabitation
If there's a dispute about whether you were actually living together as common law partners, courts look at a range of factors. No single factor is determinative—it's the overall picture that matters.
Factors Courts Consider
Factor | What Courts Look At |
|---|---|
Shared residence | Did you live at the same address? Whose name was on the lease/mortgage? Where did mail go? |
Financial interdependence | Joint bank accounts? Shared credit cards? Did you pay household expenses together? |
Social recognition | Did friends, family, and colleagues see you as a couple? Did you attend events together? |
Sexual relationship | Was there an intimate, conjugal relationship? (Not determinative on its own) |
Domestic arrangements | Did you share household responsibilities? Cook together? Do laundry together? |
Children | Did you parent children together (yours, theirs, or shared)? |
Public presentation | Did you refer to each other as spouses or partners? File taxes as common law? |
Two people can live together and NOT be common law partners—think roommates, or adult children living with parents. The question is whether you were living together as a couple in a marriage-like relationship.
Common Law vs. Married: What's the Same, What's Different
Issue | Married Couples | Common Law Couples |
|---|---|---|
Spousal support | Yes, under SSAG | Yes, under SSAG (same rules) |
Child support | Yes, under Guidelines | Yes, under Guidelines (same rules) |
Property division | Yes, automatic 50/50 under NFP | NO automatic division—keep what's yours |
Matrimonial home | Special rules apply | No special rules—regular property |
Pension splitting | Yes, automatic | No automatic right |
CPP credit splitting | Automatic on divorce | Not automatic—must apply |
Rule of 65 | Applies | Applies (same rule) |
The Big Difference: Property
This is where common law status really matters. Married couples in Ontario have automatic property equalization—the Net Family Property rules divide assets accumulated during the marriage roughly 50/50.
Common law couples? No such rules. You each keep what's in your own name. If your partner bought a house and your name isn't on it, you have no automatic claim to that house—even if you lived there for 10 years and contributed to the mortgage payments.
The only way to claim a share of your common law partner's property is through unjust enrichment—a legal claim that requires proving:
Your partner was enriched (got value)
You suffered a corresponding deprivation (lost value or contributed)
There was no legal reason (contract, gift) for the enrichment
Unjust enrichment claims are expensive, uncertain, and often don't result in a 50/50 split even when successful.
The Property Gotcha: A common law partner who gave up their career, contributed to household expenses, and helped pay the mortgage for 15 years might have strong spousal support claims—but NO automatic right to share the house their partner owns. Spousal support does not equal property division.
How Common Law Spousal Support Is Calculated
Once you establish that common law status applies, support is calculated the same way as for married couples.
The SSAG Formulas
The Spousal Support Advisory Guidelines (SSAG) apply to common law couples just like married couples:
Without children: 1.5% to 2% of income difference per year of cohabitation
With children: INDI formula targeting 40-46% of combined household income for the recipient
The duration rules are the same too:
0.5 to 1 year of support per year of cohabitation
Indefinite support if cohabitation was 20+ years or Rule of 65 applies
The Rule of 65 for Common Law
Yes, the Rule of 65 applies to common law relationships. Add the recipient's age at separation plus years of cohabitation. If it equals 65 or more (and you were together at least 5 years), support duration is indefinite.
Example: Common Law Support Calculation
Situation: Amy and Brad lived together for 8 years, no children. Amy earns $120,000, Brad earns $40,000. Brad is 45 at separation.
Income difference: $80,000
Support range (without child formula):
Low: $80,000 × 1.5% × 8 = $9,600/year = $800/month
High: $80,000 × 2% × 8 = $12,800/year = $1,067/month
Duration range: 4 to 8 years
Rule of 65: 45 + 8 = 53. Doesn't apply—support is time-limited.
Common Misconceptions
Misconception 1: "We never married, so I don't owe anything"
Reality: If you meet the common law criteria (3 years together OR child together), you may absolutely owe spousal support. The lack of a marriage certificate doesn't protect you.
Misconception 2: "Common law couples have all the same rights as married couples"
Reality: Not for property. Spousal support and child support are the same, but property division is completely different. Common law partners don't have automatic property rights.
Misconception 3: "We have to live together exactly 3 years to the day"
Reality: Courts aren't counting calendar days. If you've been living together for approximately 3 years, that's probably enough. Short breaks during an ongoing relationship usually don't reset the clock.
Misconception 4: "We kept our finances separate, so we're not common law"
Reality: Financial separation is one factor, but not determinative. Couples who keep separate bank accounts can still be common law if they share a home, present as a couple, and have a conjugal relationship.
Misconception 5: "CRA says we're common law, so we definitely are"
Reality: CRA has its own definition of common law for tax purposes (12 months of cohabitation). That's different from the Family Law Act definition (3 years or child). You can be common law for taxes but not for spousal support, or vice versa.
Cohabitation Agreements
If you're moving in with a partner and want to clarify your rights and obligations, a cohabitation agreement can help.
What a Cohabitation Agreement Can Do
Define how property will be divided if you separate
Limit or waive spousal support rights
Clarify who owns what coming into the relationship
Set expectations about financial contributions
Limitations
A cohabitation agreement can't override everything:
Child support: You can't contract out of child support obligations—it's the child's right
Spousal support waivers: Courts can override waivers if enforcing them would leave one partner in serious need or if circumstances have changed dramatically
Unconscionable terms: If the agreement is grossly unfair, courts may not enforce it
Get independent legal advice: For a cohabitation agreement to be enforceable, both parties should have independent legal advice before signing. An agreement signed without legal advice is more vulnerable to being set aside later.
Limitation Periods
There's a time limit for claiming spousal support after a common law relationship ends.
The 2-Year Rule
Under Ontario's Family Law Act, you must start a court proceeding for spousal support within 2 years of separation.
If you wait longer than 2 years, you may lose your right to claim support entirely. The clock starts ticking from the date of separation, not from when you decided to pursue a claim.
Don't wait: If you think you might have a spousal support claim against a common law partner, get legal advice promptly. Waiting too long can mean losing your rights entirely.
CPP Credit Splitting
For married couples, CPP (Canada Pension Plan) credits are automatically split upon divorce. For common law couples, it's not automatic—you have to apply.
How to Apply
Contact Service Canada and request a credit split. You'll need to provide:
Proof of cohabitation (lease, bills, statutory declaration)
Start and end dates of cohabitation
Both partners' Social Insurance Numbers
Either partner can apply—it doesn't require the other's consent. Credits earned during the cohabitation period are split 50/50.
What If We Disagree About Whether We Were Common Law?
Sometimes one partner claims the relationship was common law while the other denies it. This usually comes up when the higher-earning partner doesn't want to pay support.
Proving the Relationship
The partner claiming common law status has the burden of proving it existed. Evidence can include:
Shared lease or property ownership
Joint bank account or credit card statements
Tax returns filed as common law
Insurance policies listing each other as beneficiaries
Testimony from friends and family
Photos, social media posts showing the relationship
Shared mail at the same address
What If Evidence Is Mixed?
Courts look at the totality of the relationship. If some factors point toward common law status and others don't, the court weighs them all. There's no checklist that must be fully satisfied—it's a judgment call based on all the evidence.
To see where you stand and how much you might have to pay, there’s a free spousal support calculator (including a child support calculator) at ontariospousalsupport.com
This is not legal advice. Whether you qualify as common law partners depends on the specific facts of your relationship. The 2-year limitation period for claims is strict. If you're separating from a common law partner and have questions about support, consult with a family lawyer promptly.