The 5 C’s of Cohabitation Agreements and Marriage Contracts
Let’s be honest: nobody thinks “You know what would really spice up date night? A discussion about property division under Ontario’s Family Law Act.”
And yet, cohabitation agreements and marriage contracts (or “prenups” to most people) are one of the smartest planning tools available to couples. I find myself seeing more and more couples wanting to enter into these agreements, but they are often not sure where to start.
Far from being “unromantic,” these agreements are really about clarity, communication, and making intentional decisions together before conflict ever arises.
At Passageway Law, we often start consultations about domestic contracts using what we call the 5 C’s:
Complicated
Customizable
Consensus
Continuing obligations
Changing the law
Let’s walk through what each of those actually means.
1. Complicated
We’ll start with the least sexy one first.
Cohabitation agreements and marriage contracts are legally and financially complex documents. They intersect with:
Family law,
Property rights,
Support obligations,
Estate planning,
Tax considerations,
Business ownership,
Trusts and inheritances,
And sometimes even corporate or farm structures.
In other words: this is not a “download a template online and hope for the best” situation.
A poorly drafted agreement can create huge problems later, including some or all of the agreement being set aside entirely.
Ontario courts can overturn domestic contracts in certain circumstances, including where:
Someone did not fully disclose their finances,
One party did not understand what they were signing,
There was pressure or duress,
Or the agreement is fundamentally unfair.
So yes, they can be complicated. But that complexity exists because people’s lives are complicated.
You’re not planning for the relationship you have today. You’re trying to future-proof for the version of yourselves that may exist 5, 10, or 20 years from now.
2. Customizable
This is where domestic contracts become incredibly valuable.
Ontario’s family law system provides a default set of rules about:
Property division,
Spousal support,
Debt,
Ownership rights,
And financial obligations upon separation.
But couples are allowed to make different arrangements if they choose.
That means your agreement can be tailored to your actual life and priorities.
For example:
Maybe one spouse owns a business and wants to protect future growth.
Maybe one person is moving into the other’s pre-owned home.
Maybe there’s family wealth, an inheritance, or a cottage involved.
Maybe one spouse plans to step away from work to raise children.
Maybe you simply want more certainty than the law otherwise provides.
There is no “standard” cohabitation agreement or marriage contract because there is no standard relationship.
Some agreements are extremely simple. Others are highly sophisticated financial planning documents.
The key is making sure the agreement actually fits your relationship rather than someone else’s template from the internet.
3. Consensus
This is a big one.
A cohabitation agreement or marriage contract only works if both people voluntarily agree to it.
One person cannot force the other into signing.
That means:
Both parties need time to review the agreement,
Both should obtain independent legal advice,
There needs to be full financial disclosure,
And ideally, the process should happen well before the wedding date.
(If someone is being handed a marriage contract three days before the ceremony while relatives are already flying in, the court may later view that person’s ability to enter into the contract without duress… less than enthusiastically.)
The process itself is often valuable because it forces couples to have conversations they may otherwise avoid:
How will finances work?
What are our expectations around support?
How will we handle property ownership?
What happens if one person sacrifices career advancement for family responsibilities?
These are not always easy conversations. But they are important ones.
And frankly, discussing expectations calmly now is usually much easier than litigating assumptions later.
Finally, it will be a much more cost effective process if the couple has consensus about the purpose of the agreement before retaining lawyers.
4. Continuing Obligations
A lot of people think signing the agreement is the end of the process. It’s usually not.
Domestic contracts often create ongoing responsibilities throughout the relationship. For instance, if parties have agreed to be legally separate as to property, that will (and should) influence how the parties structure their own careers and family responsibilities to protect themselves down the line.
Other obligations that the agreement may create could be:
Maintaining separate property records,
Keeping inherited funds separate,
Updating financial disclosures,
Following agreed-upon ownership structures,
Maintaining insurance obligations,
Or updating agreements as life circumstances change.
And life does change. People buy and sell homes, sell businesses, have children, change careers, move, receive inheritances, etc.
An agreement drafted for a couple in their late twenties renting a condo downtown may need revisiting fifteen years later when there are kids, corporations, investment properties, and a family cottage in the picture.
A good domestic contract is not necessarily static. It should evolve with your life. Even where the contract itself doesn’t get updated, it should still inform how financial decisions are made throughout the duration of the relationship.
5. Changing the Law
This is ultimately the entire point.
Marriage contracts and cohabitation agreements exist because couples may want outcomes that differ from what Ontario law would otherwise impose.
Without an agreement, Ontario family law applies by default. Without understanding the default, it’s hard to understand how and why that may need to be changed. This is why retaining an experienced family lawyer to help with this process is crucial.
Sometimes, after an explanation from an experience family lawyer, people are perfectly happy with those default rules. Other times, they are not.
For example:
A spouse may want to protect business growth from equalization.
A family may want inherited property to remain excluded.
A couple may want certainty around spousal support.
One party may want protection after making career sacrifices for the relationship.
Common law spouses may want rights and obligations clarified because Ontario law treats married and unmarried couples differently in important ways.
Domestic contracts allow couples to proactively define those rights and obligations themselves rather than leaving everything to legislation or future court decisions.
In many ways, these agreements are less about mistrust and more about intentional planning.
They allow couples to decide:
“We would prefer this arrangement instead of the default one the law would otherwise impose.”
Final Thoughts
Cohabitation agreements and marriage contracts are not about expecting failure.
They are about:
clarity,
communication,
risk management,
and thoughtful planning.
At their best, they reduce uncertainty, prevent future conflict, and help couples move forward with a shared understanding of expectations.
At Passageway Law, we help clients approach these conversations in a practical, respectful, and collaborative way. Because while the legal side matters, the relationship dynamics matter too.
And ideally, everyone leaves the process still wanting to attend the wedding.
Disclaimer: This blog is intended for informational purposes only and does not constitute legal advice. If you are considering a cohabitation agreement or marriage contract, you should speak with a family lawyer about your specific circumstances.