Legally enforceable cohabitation or prenup agreements can be highly useful domestic contracts when a couple decides to move in with each other or get married, saving time, expense, and stress if the relationship breaks down.

However, the British Columbia courts can set aside these agreements on various grounds. Both cohabitation and prenuptial agreements may be rendered useless if they were not drafted in compliance with the BC Family Law Act.

An agreement that cannot be upheld in court can create high-stakes issues for couples who separate and expect not to have to deal with these issues.

So, while it is not a legal requirement to hire a lawyer to draft a cohabitation or prenup agreement in B.C., it is highly recommended for family lawyers to be involved in the process.

What is a cohabitation agreement in BC?

A cohabitation agreement (sometimes called a “cohab”) is a legally binding domestic contract between unmarried partners who live together or plan to move in together in a marriage-like relationship.

In BC, under the Family Law Act, once you have lived with a partner for two years, the law treats you as “spouses”, enjoying most of the same rights and responsibilities as married couples.

A cohabitation agreement typically covers:

Property and debt division: Who owns what, and how will assets and debts be apportioned if the couple separates?
Spousal support: Whether one partner will be responsible for support payments and, if so, how much, how often, and for how long?
Financial contributions: How will household expenses, such as bills, rent, or mortgage payments, be divided during the relationship?

What is a prenuptial agreement in BC?

While the name is different, a prenuptial agreement (“prenup”) is practically the same as a “cohab” in that it details how partners will deal with the main financial issues during the relationship and if the relationship ends.

This type of contract is made before the marriage starts. If a contract is drafted after the marriage has begun, it is known as a “postnuptial” agreement, again serving the same purpose.

Can you draft a cohabitation agreement without a lawyer?

No B.C. law stipulates that couples must hire a lawyer to create a marriage or cohabitation contract. The reality is, however, that the risk of a cohabitation or prenup agreement being set aside when “push comes to shove” is much higher if you choose not to seek legal assistance.

There is a significant difference between what is “legally required” to sign a piece of paper and what is “legally required” for that paper to hold up in a courtroom years later.

The Family Law Act respects the autonomy of couples to make their own deals. If challenged, however, the courts maintain a “watchdog” role to ensure deals are fair and legally sound.
First, understand the basic legal requirements for a cohab or prenup agreement to be valid:

It must be in writing.
It must be signed voluntarily by both partners.
Full financial disclosure from both parties is required.
The agreement cannot be unconscionably unfair.

Common legal pitfalls with marriage and cohab agreements

Even agreements that are complete and executed in apparent accordance with the legal requirements may be heavily scrutinized by B.C. judges.

The most common reasons for agreements to be set aside by the B.C. courts include:

The failure to disclose assets or debts: Hidden financial information not known by one party at the time the agreement was created.
The lack of independent legal advice by one party: Leading the judge to conclude that the individual did not understand the consequences of signing the document.
Improper advantage or undue influence: The “power dynamic” during the signing of the agreement leads a judge to conclude that it was signed under duress or due to a partner’s vulnerability.
Significant unfairness: The judge concludes that the agreement cannot stand, based on the length of the relationship or drastic changes in value.
Unconscionability: The terms are so one-sided and unfair that they “shock the conscience”.

Each of these reasons can cause an agreement to be declared invalid and unexpected financial obligations or legal battles to ensue for the couple, defeating the original purpose of the agreement.

Note, too, that the failure to consider future changes in life circumstances, such as an agreement that doesn’t account for children or drastic financial shifts, may not hold up in court.

So, while not using a lawyer to draft your contract may seem like a valuable money-saving exercise, it can backfire and lead to severe and unexpected legal and financial consequences.

A seasoned marriage contract lawyer will look out for potential red flags that could result in the types of unwanted consequences outlined above.

Why should a lawyer draft your cohabitation or prenup agreement?

You should have a lawyer draft your cohabitation or prenup agreement for one main reason: the likelihood of the agreement protecting you, standing up in court, and not being overturned is far lower.

An experienced family lawyer will:

Ensure full financial disclosure.
Help you seek fair and reasonable terms.
Provide legal advice (your partner should also seek independent legal advice from a different lawyer).
Include clauses that address major life changes in the future.

Do both parties need a separate family lawyer for a BC cohab or prenup?

For the couples to satisfy the recommendation to obtain independent legal advice in B.C., each partner must hire a separate family lawyer during the process.

A couple cannot “share” a lawyer to save money. Doing so will offer little protection from a judge overturning the agreement if it is challenged in court.

When both parties are represented by lawyers, they can create a significantly stronger agreement. It should satisfy a judge that both parties understood their rights, the terms of the agreement, and its legal implications when it was created.

Remember, without seeking independent legal advice, couples can end up in a worse financial position than if they had no agreement at all.

For a free 30-minute consultation about your legal options for creating agreements before or after marriage or cohabitation has begun, contact the team at Legalbird today.

Date Modified:

March 26, 2026

Kawal Atwal

Family Law Expertise You Can Trust

Benti K. Atwal is a British Columbia family law lawyer who focuses on separation, divorce, parenting disputes, child support, spousal support, and property division. She takes a client-centered, trauma-informed approach, understanding that family law matters involve both complex legal issues and significant personal impact. Benti represents clients through negotiation, mediation, and court proceedings, advocating firmly when litigation is necessary while encouraging resolution where possible.

Her practice includes parenting arrangements, parenting time, parental responsibilities, guardianship, Section 7 expenses, support claims, and the division of family property and debt. She also assists with separation agreements, prenuptial agreements, and cohabitation agreements under British Columbia law. Benti speaks fluent Punjabi and conversational French and Gujarati, allowing her to serve a diverse range of families across BC with clarity and cultural sensitivity.