A Canadian prenup is strongest when it does a focused job: it explains how two people want to handle property, debts, business interests, support, and financial disclosure if the relationship ends. It is usually weaker when it tries to control future children, punish personal behaviour, avoid disclosure, or override rules that a court must still supervise.
That distinction matters for couples who are ready to buy a prenup template, use an online prenup service, or bring a draft to a family lawyer. A clear draft can save time. A draft filled with terms that cannot work can create false confidence, extra legal fees, and a harder conversation with your partner.
This guide explains what cannot be included in a prenup in Canada, what can usually be handled in a careful way, and how to turn those limits into a better drafting checklist.
Quick answer: what cannot be included in a prenup in Canada?
A Canadian prenup should generally avoid clauses that:
- decide future parenting time or decision-making responsibility for children
- waive or predetermine child support in a way that conflicts with child support guidelines
- hide assets, skip financial disclosure, or prevent either partner from understanding the agreement
- create unfair or unconscionable support or property results
- punish personal behaviour through lifestyle penalties that are not tied to real financial planning
- override province-specific signing, witnessing, notarial, or legal advice requirements
- interfere with third-party rights, tax rules, creditors, or pension plan rules
That does not mean a prenup is narrow. It can still be very useful. A well-built Canadian prenup can cover how premarital property is treated, how business growth is handled, how debt is allocated, what happens to gifts or inheritance, whether spousal support is limited or structured, and what financial records each partner exchanged before signing.
For a broader validity overview, see Prenuply's guide to whether prenups are enforceable in Canada. For drafting ideas that usually belong in the agreement, see important prenup clauses Canadian couples often miss.
What Canadian prenups can usually cover
Before looking at the limits, it helps to understand the normal lane for a prenup. Across Canada, the strongest clauses tend to focus on financial rights and obligations between spouses.
Common prenup topics include:
- Premarital assets: homes, savings, investments, pensions, vehicles, professional corporations, business shares, and valuables owned before marriage
- Growth in value: whether increases in value during marriage are shared, excluded, or shared only in a defined way
- Business ownership: how a company, partnership interest, shareholder loan, retained earnings, goodwill, or future sale proceeds are treated
- Debts: who is responsible for student loans, tax debt, credit lines, business debt, guarantees, and debts brought into the marriage
- Inheritance and gifts: how future gifts or inheritances should be kept separate, documented, or traced
- Spousal support: whether support is waived, limited, reviewed, or calculated using agreed factors, subject to provincial law and court review
- Disclosure process: schedules of assets, debts, income, supporting documents, and acknowledgments that each partner had time to review the draft
Ontario's Family Law Act section 52, for example, says marriage contracts can address ownership or division of property, support obligations, certain child education or moral training matters, and other matters in the settlement of the spouses' affairs. It also says a marriage contract cannot limit a spouse's rights under Ontario's matrimonial home rules.
British Columbia takes a similar financial-planning approach for property and debt. Under BC's Family Law Act section 92, spouses can make agreements about dividing family property and family debt, including equal or unequal division, including or excluding property or debt, and valuing property or debt differently.
The practical lesson: a prenup should be specific about money, property, and financial process. It should not pretend to be a complete court order for every future family issue.
Limit 1: future parenting time and decision-making responsibility
The clearest category to avoid is a clause that tries to decide future parenting time or decision-making responsibility for children before there is an actual separation and before the child's circumstances are known.
In everyday language, this means a prenup should not say things like:
- future children will live mainly with one parent
- one partner will have final say over education or health decisions after separation
- one parent gives up parenting time in advance
- parenting schedules are fixed before any child exists, ages, needs, school routine, or safety issue is known
Ontario's Family Law Act is explicit on this point for marriage contracts. Section 52 allows limited terms about education and moral training, but not decision-making responsibility or parenting time. Section 56 also allows a court to disregard child-related domestic contract provisions when doing so is in the best interests of the child.
The federal Divorce Act also uses parenting terminology such as parenting time and decision-making responsibility, and courts focus on the child's best interests when parenting issues are decided.
A prenup can still help parents indirectly. It can reduce financial conflict, clarify who owns what, and create a calmer record of financial disclosure. But parenting arrangements should be handled when they are actually needed, with current information about the child.
Limit 2: waiving child support or setting child support too low
Child support is not just a private debt between adults. It is tied to the child's legal right to financial support.
That is why prenup clauses like these are risky:
- neither parent will ever pay child support
- one parent accepts a fixed low amount regardless of income
- a parent waives child support in exchange for keeping property
- a future child will be supported only if one partner chooses to do so
Justice Canada's child support guidance says children need financial support from their parents and have a legal right to it. The Federal Child Support Guidelines are designed to establish fair support standards, reduce conflict, and make child support calculations more objective.
Ontario's Family Law Act section 56 goes further for domestic contracts. A court may disregard a child support provision if it is unreasonable having regard to the child support guidelines and the rest of the child support terms in the contract.
A better approach is to leave child support to the applicable law at the time. If the agreement mentions children, it should usually say that child support will be determined under the applicable legislation and guidelines when the issue arises.
Limit 3: hiding assets, skipping disclosure, or using vague schedules
A prenup can fail because of process, not only because of wording. Financial disclosure is one of the biggest process issues.
A risky draft says something like: each partner is satisfied with disclosure, even though no real assets, debts, income, business records, or property values are attached. A stronger draft includes schedules, approximate values, debt balances, ownership details, and a record of documents exchanged.
Ontario's Family Law Act section 56 says a court may set aside a domestic contract or a provision if a party failed to disclose significant assets, debts, or other liabilities existing when the contract was made. BC's Family Law Act section 93 similarly identifies failure to disclose significant property, debts, or other relevant information as a reason a court may set aside or replace a property and debt agreement.
That is why a prenup should not include a clause that tries to excuse incomplete disclosure. It should do the opposite. It should make disclosure easier to verify.
Useful disclosure attachments can include:
- real estate addresses, ownership percentages, mortgages, and appraisals or estimates
- bank and investment account summaries
- business ownership documents, shareholder agreements, or accountant summaries
- tax returns or notices of assessment
- credit card, student loan, line of credit, and tax debt balances
- pension, RRSP, TFSA, and employer benefit statements
- expected gifts, inheritances, or family trust interests, where known
Prenuply's financial disclosure checklist for prenups in Canada walks through this in more detail.
Limit 4: unfair waivers that ignore real life
A prenup can address spousal support, but that does not mean every support waiver is equally strong. Courts may review support clauses when they create harsh, unexpected, or unconscionable outcomes.
Risky support terms include:
- a total spousal support waiver where one partner expects to leave the workforce for children or family care
- a waiver signed right before the wedding with little review time
- a support cap that ignores a major income gap or disability
- a clause that benefits only one partner after incomplete disclosure
- a clause that forces one partner into financial hardship while the other keeps nearly all wealth created during the marriage
This does not mean support planning is pointless. It means support terms should be realistic and reviewed. A couple might agree to limit support in short marriages, set a review trigger if children are born, or use a formula that reflects income, caregiving, and marriage length.
A good drafting question is: would both people still understand this clause if they had to explain it to their own family lawyer two years from now?
Limit 5: lifestyle penalties and personal conduct rules
Some couples ask whether a prenup can include lifestyle clauses. Examples include penalties for infidelity, chores, weight gain, social media behaviour, family visits, or intimacy.
These clauses often distract from the financial purpose of the agreement. They can also create enforceability problems, privacy problems, or evidence problems if someone later has to prove what happened.
Ontario's Family Law Act even has a specific rule about certain chastity-related clauses. Section 56 says a provision in a domestic contract that takes effect on separation and makes a right dependent on remaining chaste is unenforceable.
For most couples, the better approach is simple: do not use the prenup to police the relationship. Use it to organize financial expectations.
If a personal issue has real financial consequences, translate it into a neutral financial clause. For example, instead of a penalty for one partner being irresponsible with money, consider a clause about separate credit card debt, personal guarantees, business liabilities, or spending from joint accounts.
Limit 6: clauses that ignore the matrimonial home or family residence rules
Homes deserve special care because some provinces have rules that cannot be reduced to a simple ownership label.
Ontario is the classic example. Section 52 of Ontario's Family Law Act says a provision in a marriage contract that purports to limit a spouse's rights under Part II, the matrimonial home part, is unenforceable. That does not mean home planning is impossible. It means Ontario home clauses need careful legal review, especially where one partner owned the house before marriage and it becomes the matrimonial home.
Quebec has its own structure. The Government of Quebec says a marriage contract must be notarized, and that spouses can use one to choose or change a matrimonial regime. Quebec's matrimonial regime guidance also explains that couples without a contract are governed by the default legal regime.
The takeaway is practical. If your prenup deals with a home, title alone is not enough. Your draft should identify:
- who owns the home now
- whether it will be a family or matrimonial home
- who pays the mortgage, taxes, insurance, repairs, and renovations
- whether value growth is shared
- how sale proceeds are divided
- whether province-specific occupancy, consent, or family residence protections may apply
Limit 7: clauses that ignore provincial signing rules
A prenup is not just content. It is also execution.
Different provinces use different language and formalities. Ontario requires domestic contracts to be in writing, signed by the parties, and witnessed. BC requires written property and debt agreements to be signed by each spouse with each signature witnessed for the section 93 set-aside framework. Alberta's Family Property Act has its own formalities for family property agreements, and Alberta couples commonly need separate legal advice and acknowledgment certificates. Quebec marriage contracts must be signed before a notary.
This is why a clause saying both partners agree to skip provincial formalities is not useful. A better agreement builds the signing process into the plan:
- each partner has enough time to review the draft before the wedding
- each partner has access to independent legal advice
- financial disclosure schedules are attached before signing
- witnesses, notaries, certificates, or acknowledgments are handled for the province
- the final signed copy is stored somewhere both partners can access
If you are still early in the process, Prenuply's 8-step guide to creating a prenup in Canada is a good next read.
Better wording: practical examples
Here are simple examples of how to keep a prenup in the right lane.
| Goal | Risky wording | Better drafting direction |
|---|---|---|
| Protect a business | My spouse gets nothing from my company under any circumstances. | Identify the company, current value, ownership, retained earnings, shareholder loans, future growth, and whether any marital contribution changes the result. |
| Address future children | If we separate, the children will live with Partner A. | State that parenting and child support will be decided under applicable law at the time, with the child's best interests and support guidelines respected. |
| Limit spousal support | Neither person can ever ask for support. | Use a reviewed support waiver, cap, review trigger, or formula that considers marriage length, income gap, caregiving, disability, and fairness. |
| Keep inheritance separate | Any inheritance is mine forever. | Require inherited funds to be disclosed, documented, kept in a separate account where intended, and traced if used for shared property. |
| Handle debts | We are not responsible for each other's debts. | List known debts, assign responsibility, address refinancing, guarantees, tax liabilities, joint accounts, and debts incurred for family purposes. |
The better direction is not always longer. It is more precise.
A drafting checklist before you publish, print, or sign
Use these questions before sending a draft for legal review:
- Is the clause financial? If it is about property, debt, business ownership, disclosure, or support, it is probably in the right subject area.
- Does it affect children? If it tries to decide parenting time, decision-making responsibility, or child support in advance, revise it with a lawyer.
- Can both partners understand it? Plain language matters. A confusing clause is harder to defend.
- Is disclosure attached? Do not rely only on a general statement that disclosure happened.
- Is the result fair enough to explain? One-sided agreements are not automatically invalid, but extreme terms need careful review.
- Does the province require a special signing step? Check witnessing, notarial, acknowledgment, and independent legal advice expectations.
- Is there enough time before the wedding? Signing under pressure creates avoidable risk.
Prenuply can help you organize the financial topics and create a Canadian prenup draft for lawyer review. If you are ready to start, you can create your prenup template and use the draft as a structured starting point for independent legal advice.
FAQ: clauses Canadian prenups should avoid
Can a prenup decide custody in Canada?
A prenup should not try to decide future custody, now commonly discussed as parenting time and decision-making responsibility. Parenting arrangements depend on the child's best interests at the time decisions are made. A prenup can reduce financial conflict, but it should not be treated as a final parenting plan for future children.
Can a prenup waive child support?
A prenup should not waive child support or set child support in a way that conflicts with applicable guidelines. Child support is connected to the child's right to support, not only the parents' private bargain.
Can a prenup waive spousal support?
Sometimes couples include spousal support waivers or limits, but they need careful drafting and legal review. A support clause may be vulnerable if there was poor disclosure, pressure, lack of understanding, or an outcome that is unconscionable or unfair under the applicable law.
Can a prenup include an infidelity clause?
Some couples ask for infidelity clauses, but they are often a poor fit for a Canadian prenup. They can be hard to prove, emotionally charged, and disconnected from the financial planning purpose of the agreement. If the real concern is financial conduct, address debt, spending, accounts, or property directly.
Can a prenup protect a house bought before marriage?
Often, yes, but home clauses are province-sensitive. Ontario's matrimonial home rules are especially important because a marriage contract cannot simply remove statutory matrimonial home rights. Read more in Prenuply's guide to Ontario prenups and the matrimonial home.
What happens if our prenup already includes a risky clause?
Do not panic, but do not ignore it. A lawyer may be able to revise the clause, add disclosure schedules, create an amendment, or explain whether the rest of the agreement can still stand. The best time to fix a risky clause is before anyone relies on it.
Bottom line
The best Canadian prenups are not aggressive. They are clear, financial, disclosed, and province-aware.
If a clause is about property, debts, business interests, inheritance, support, or disclosure, it may belong in the agreement. If it is about future parenting, child support waivers, hidden assets, personal punishment, or bypassing provincial formalities, it likely needs to be removed or rewritten before signing.
This article provides general information about Canadian prenuptial agreements. It is not legal advice. Prenuply AI Inc. is not a law firm and does not provide legal services. For advice about your specific situation, consult a qualified family lawyer in your province.