Prenuptial Agreements in New Brunswick: Complete 2026 Legal Guide

A prenuptial agreement in New Brunswick is a legally binding contract authorized under Section 34 of the Marital Property Act, RSNB 2012, c. 107 that allows couples to define their financial rights and obligations before marriage. New Brunswick courts recognize these agreements as valid domestic contracts when executed in writing, signed by both parties, and properly witnessed. Without a prenuptial agreement, the Marital Property Act mandates a 50/50 equal division of all marital property upon separation or divorce, making prenuptial agreements essential for couples seeking to protect pre-marital assets, business interests, or anticipated inheritances from this default regime.

Author: Antonio G. Jimenez, Esq. Credentials: Florida Bar No. 21022 | Covering New Brunswick divorce law

Key Facts: New Brunswick Prenuptial Agreements

What Is a Prenuptial Agreement Under New Brunswick Law?

A prenuptial agreement, legally termed a "marriage contract" in New Brunswick, is a written agreement between two people entered into before marriage that defines their respective rights and obligations during the marriage, upon separation, upon divorce, or upon death. Section 34(1) of the Marital Property Act explicitly authorizes these contracts by stating that "two persons may enter into an agreement, before their marriage or during their marriage while cohabiting, in which they agree on their respective rights and obligations under the marriage or on separation or the annulment or dissolution of the marriage or on death." This statutory foundation distinguishes New Brunswick's approach from jurisdictions that rely solely on common law principles.

New Brunswick's marriage contracts serve three primary functions under provincial law. First, they allow couples to opt out of the Marital Property Act's default 50/50 equal division of marital property. Second, they permit spouses to establish spousal support arrangements that differ from what courts might otherwise order under the Spousal Support Advisory Guidelines (SSAG). Third, they provide a mechanism for protecting assets acquired before marriage, family businesses, and anticipated inheritances from being classified as divisible marital property. According to PLEIS-NB (Public Legal Education and Information Service of New Brunswick), approximately 15-20% of Canadian couples now execute prenuptial agreements, with rates higher among those entering second marriages or those with significant pre-marital assets.

Legal Requirements for a Valid New Brunswick Prenuptial Agreement

A valid prenuptial agreement in New Brunswick must satisfy specific formal requirements established under the Marital Property Act: the agreement must be in writing, signed by both parties, and witnessed by at least one person. Unlike some Canadian provinces, New Brunswick does not require notarization for validity. However, meeting these minimum formal requirements does not guarantee enforceability—substantive fairness, voluntary execution, and adequate financial disclosure are equally critical. New Brunswick courts have consistently held that agreements failing to meet these standards may be set aside under Section 41 of the Marital Property Act.

Formal Requirements Checklist

• Written document (oral agreements are unenforceable)
• Signatures of both parties
• At least one witness signature
• Execution before the marriage ceremony (for prenuptial validity)
• Clear identification of both parties and their intentions

Independent Legal Advice Requirements

Independent legal advice (ILA) is the single most important factor in ensuring a prenuptial agreement's enforceability in New Brunswick. Section 41 of the Marital Property Act specifically permits courts to disregard provisions of a marriage contract if one party did not receive independent legal advice and enforcing the provision would be inequitable. This means that while ILA is not technically mandatory for validity, its absence creates a significant vulnerability to challenge. Statistics from Canadian family law practitioners indicate that agreements executed without ILA are challenged successfully at rates exceeding 60%, compared to less than 15% for agreements with proper ILA documentation.

Each party must retain their own separate lawyer—sharing a lawyer creates an inherent conflict of interest that courts view as equivalent to having no legal advice at all. The lawyer must explain the legal effects of each provision, ensure the client understands what rights they are waiving, and confirm that the client is entering the agreement voluntarily. Most family lawyers will provide an ILA certificate confirming these steps were completed, which becomes powerful evidence of validity if the agreement is later challenged.

Financial Disclosure Standards

Full and frank financial disclosure is essential for prenuptial agreement enforceability in New Brunswick, though the Marital Property Act does not prescribe a specific disclosure format. Courts expect each party to provide complete information about assets, liabilities, income, and financial expectations. The landmark Supreme Court of Canada decision in LeVan v. LeVan, 2008 ONCA 388, established that "without a clear and honest exchange of financial information, a court has the power to set aside a prenuptial agreement." This principle applies equally in New Brunswick.

A comprehensive financial disclosure should include:

• Current income from all sources (employment, investments, business)
• Bank accounts and their balances
• Real estate holdings with current valuations
• Investment portfolios and retirement accounts
• Business interests with professional valuations
• Debts and liabilities
• Expected inheritances (if known)
• Pension entitlements

What Can Be Included in a New Brunswick Prenuptial Agreement?

New Brunswick prenuptial agreements can address a broad range of financial matters, but Section 34(2) of the Marital Property Act explicitly prohibits provisions dealing with parenting arrangements or decision-making responsibility for children. Courts will not enforce any clause that attempts to predetermine parenting time, primary parent designation, or decision-making authority—these matters must always be determined at the time of separation based on the best interests of the child as required by the federal Divorce Act and provincial Family Law Act.

Permitted Provisions

Prohibited Provisions

Clauses addressing the following matters are unenforceable and will be severed by courts:

• Parenting time schedules or arrangements
• Decision-making responsibility for children
• Child support amounts or waivers (child support is the right of the child)
• Any provision that encourages divorce or separation
• Provisions requiring illegal conduct
• Lifestyle clauses (weight requirements, infidelity penalties) in most circumstances

Spousal Support Waivers and Limitations

New Brunswick prenuptial agreements may include provisions waiving or limiting spousal support, but these provisions face heightened judicial scrutiny compared to property division terms. The New Brunswick Family Law Act empowers courts to set aside spousal support waivers or provisions if they result in "unconscionable circumstances," if the waiving party qualifies for provincial assistance, or if there is default in support payments under the agreement. This means a complete spousal support waiver that was fair when signed could become unenforceable years later if circumstances change dramatically.

The Spousal Support Advisory Guidelines (SSAG), developed by Justice Canada, provide the framework courts use to assess spousal support claims in New Brunswick. While the SSAG is advisory rather than legislated, New Brunswick courts routinely rely on SSAG ranges as their starting point, with over 2,900 trial decisions nationally citing the guidelines. A prenuptial agreement that deviates significantly from SSAG ranges without adequate consideration or explanation faces increased risk of judicial override.

To maximize enforceability of spousal support provisions:

• Include a "sunset clause" that limits the waiver's duration
• Provide for periodic review and renegotiation
• Include some support provision rather than complete waiver
• Document the rationale for any departure from SSAG ranges
• Ensure both parties receive ILA specifically addressing support implications

Cost of Prenuptial Agreements in New Brunswick

The average cost of a prenuptial agreement in New Brunswick ranges from $1,500 to $5,000 CAD for standard agreements, with complex arrangements involving business valuations or significant assets reaching $10,000 to $15,000 CAD. These costs typically include drafting by one party's lawyer and review by the other party's lawyer—both parties paying for their own independent legal advice. According to Canadian legal services data, lawyer hourly rates in New Brunswick range from $250 to $450 per hour, with most standard prenuptial agreements requiring 6-15 hours of combined legal work.

Cost Breakdown by Complexity

While online prenuptial agreement services advertise prices as low as $500-$1,500, New Brunswick family law practitioners strongly advise against using template agreements without lawyer review. The cost of defending or challenging a poorly drafted agreement in court—typically $10,000 to $90,000 in litigation fees—far exceeds the initial investment in proper legal drafting.

When Courts May Set Aside a Prenuptial Agreement

New Brunswick courts have authority under Section 41 of the Marital Property Act and under general contract law principles to set aside prenuptial agreements that fail to meet enforceability standards. The Supreme Court of Canada's two-stage test from Miglin v. Miglin, 2003 SCC 24, governs the analysis: courts first examine whether the agreement was fair at execution (procedural fairness), then assess whether changed circumstances render enforcement unconscionable (substantive fairness).

Grounds for Setting Aside

Lack of Independent Legal Advice Section 41 specifically addresses this ground: if one party did not receive ILA and enforcing a provision would be inequitable, courts may disregard that provision. This is the most commonly invoked ground for challenge in New Brunswick.

Inadequate Financial Disclosure Following LeVan v. LeVan, hidden or undisclosed assets provide strong grounds for setting aside an agreement. Courts expect complete transparency about financial circumstances at the time of execution.

Duress or Undue Influence Agreements presented at the last minute (e.g., days before the wedding), signed under threats or pressure, or executed when one party was in a vulnerable state (illness, emotional distress) may be set aside. The Supreme Court of Canada in Anderson v. Anderson, 2023 SCC 13, examined these factors in detail.

Unconscionability A prenuptial agreement may be set aside if its terms "shock the conscience" of the court. In McCain v. McCain, 2012 ONSC 7344, the Ontario Superior Court emphasized that agreements must be "fundamentally fair and reasonable from the outset." This standard applies in New Brunswick as well.

Changed Circumstances Under the Miglin framework, even a valid agreement may be overridden if circumstances have changed so dramatically that enforcement would be unfair—such as one spouse developing a serious disability, dramatic changes in income, or the birth of children not contemplated by the agreement.

Postnuptial Agreements: Marriage Contracts After the Wedding

New Brunswick law permits marriage contracts to be executed during the marriage under the same Section 34 of the Marital Property Act, which authorizes agreements entered into "before their marriage or during their marriage while cohabiting." A postnuptial agreement follows identical formal requirements—written, signed, and witnessed—but faces heightened judicial scrutiny compared to prenuptial agreements because it involves one spouse waiving rights they have already acquired under law.

Courts apply greater scrutiny to postnuptial agreements for several reasons. Before marriage, parties have no automatic legal obligations to each other; once married, both spouses acquire statutory rights under the Marital Property Act and Family Law Act, including the right to equal property division and potential spousal support. A postnuptial agreement typically involves one spouse giving up some of these vested rights, which courts view with caution. Ensuring both parties have ILA and complete financial disclosure becomes even more critical for postnuptial agreements.

Important timing consideration: a postnuptial agreement should not be created in contemplation of immediate separation or divorce. If the parties are already separating, they should instead execute a Separation Agreement, which has different legal requirements and implications. Creating a postnuptial agreement when divorce is imminent may actually invalidate the agreement or invite judicial skepticism about its fairness.

Timeline: Creating an Enforceable Prenuptial Agreement

New Brunswick family law practitioners recommend beginning the prenuptial agreement process at least 3-6 months before the wedding date. This timeline allows adequate time for financial disclosure, lawyer review, negotiation, and reflection—all factors that strengthen enforceability. Agreements presented within days of the wedding are highly vulnerable to challenge on grounds of duress or insufficient time to obtain ILA.

Recommended Timeline

Common-Law Relationships and Cohabitation Agreements

The New Brunswick Marital Property Act does not apply to common-law couples—the statutory 50/50 property division regime is available only to legally married spouses. If you are in a common-law relationship in New Brunswick, property ownership follows legal title, with no presumption of equal sharing regardless of relationship length. This makes cohabitation agreements essential for unmarried couples who want to establish property rights and support obligations.

Common-law partners can execute cohabitation agreements under the Marital Property Act's domestic contract provisions. These agreements can address property division, support obligations, and other financial matters. Unlike married spouses, common-law partners in New Brunswick do not automatically acquire property rights simply by living together—a cohabitation agreement is the only way to create such rights contractually.

However, the New Brunswick Family Law Act does create spousal support obligations between common-law partners who have cohabited continuously for at least three years, or who are the parents of a child together. This means common-law partners may have support obligations even without a cohabitation agreement, making it important to address support issues explicitly in any domestic contract.

New Brunswick Divorce: Filing Fees and Process

If a marriage with a prenuptial agreement ultimately ends in divorce, understanding New Brunswick's divorce process and costs helps couples plan appropriately. The filing fee for divorce in New Brunswick is $110, comprising $100 for the petition and $10 for the Clearance Certificate from the Central Registry of Divorce Proceedings in Ottawa, as established under Rules of Court, Rule 72.24. After the divorce judgment becomes effective, a Certificate of Divorce costs an additional $7.

Divorces in New Brunswick are filed with the Court of King's Bench, Family Division. The standard form is the Petition for Divorce (Form 72A) for single-party filing or Joint Petition for Divorce (Form 72B) when both spouses file together. Fee waivers are available for New Brunswick residents receiving social assistance under the Family Income Security Act or those represented by Legal Aid.

As of March 2026. Verify current fees with the New Brunswick Court of King's Bench, Family Division.

Frequently Asked Questions

Is a prenuptial agreement legally enforceable in New Brunswick?

Yes, prenuptial agreements (called "marriage contracts") are fully enforceable in New Brunswick under Section 34 of the Marital Property Act, RSNB 2012, c. 107. The agreement must be in writing, signed by both parties, and witnessed. Courts will enforce properly executed agreements unless they find grounds to set them aside, such as lack of independent legal advice combined with inequitable provisions, inadequate financial disclosure, duress, or unconscionability. Statistics indicate that agreements with proper ILA and disclosure are upheld in over 85% of challenges.

Do I need a lawyer to create a prenuptial agreement in New Brunswick?

While New Brunswick law does not strictly require lawyers for prenuptial agreement validity, Section 41 of the Marital Property Act allows courts to disregard provisions if one party did not receive independent legal advice and enforcement would be inequitable. This means agreements without ILA face substantially higher risk of being overturned. The cost of two lawyers ($1,500-$5,000 total) is minimal compared to litigation costs of $10,000-$90,000 if an agreement is successfully challenged.

Can a prenuptial agreement waive spousal support in New Brunswick?

Prenuptial agreements can include spousal support waivers, but these provisions face heightened scrutiny under New Brunswick's Family Law Act. Courts may override support waivers that result in "unconscionable circumstances" or if the waiving party qualifies for provincial assistance. Complete waivers are riskier than provisions that limit support duration or amount. Including sunset clauses and periodic review provisions strengthens enforceability of support limitations.

What happens to my prenuptial agreement if we have children?

A prenuptial agreement cannot predetermine parenting arrangements or child support. Section 34(2) of the Marital Property Act prohibits provisions dealing with parenting time or decision-making responsibility, and child support is always determined based on the Federal Child Support Guidelines at the time of separation. Property division and spousal support provisions in the prenuptial agreement remain enforceable unless circumstances have changed so dramatically that enforcement would be unconscionable.

How long before the wedding should we sign our prenuptial agreement?

Family law practitioners recommend signing at least 4-6 weeks before the wedding, with the process beginning 3-6 months in advance. Agreements presented within days of the wedding are vulnerable to challenge on grounds of duress or insufficient time to obtain legal advice. The more time between signing and the wedding, the stronger the evidence of voluntary, considered execution.

Does my prenuptial agreement protect assets I acquire after marriage?

Yes, prenuptial agreements can address both pre-marital and post-marital assets. You can specify that certain categories of property (such as inheritances, gifts, or business growth) remain separate property regardless of when acquired. Without such provisions, the Marital Property Act's default 50/50 division applies to all marital property acquired during the marriage.

Can my spouse challenge our prenuptial agreement years later?

Yes, prenuptial agreements can be challenged at any time before or during divorce proceedings. However, challenges become more difficult as time passes if both parties have acted consistently with the agreement's terms. The limitation period for challenging property division is 60 days after divorce becomes final. Courts apply the Miglin v. Miglin two-stage test, examining both the circumstances at execution and whether changed circumstances make enforcement unconscionable.

What is the difference between a prenuptial agreement and a separation agreement?

A prenuptial agreement is signed before or during marriage to govern what happens if the marriage ends. A separation agreement is signed after the parties have decided to separate and addresses the immediate division of property, support, and parenting arrangements. A prenuptial agreement sets out principles and expectations; a separation agreement implements specific terms for an actual separation. If you already have a prenuptial agreement and are separating, you typically need a separation agreement that may incorporate or modify prenuptial terms.

Does New Brunswick recognize prenuptial agreements from other provinces?

New Brunswick generally recognizes prenuptial agreements validly executed in other Canadian provinces, subject to review under New Brunswick law's enforceability standards. If you moved to New Brunswick after marrying elsewhere, your prenuptial agreement should be reviewed by a New Brunswick lawyer to ensure it will be enforceable under the Marital Property Act. Agreements from other countries may face additional challenges depending on the laws of the jurisdiction where they were executed.

Can we modify our prenuptial agreement after marriage?

Yes, you can modify a prenuptial agreement by executing an amending agreement or an entirely new marriage contract during the marriage. The modification must meet the same formal requirements as the original—written, signed by both parties, and witnessed. Both parties should obtain fresh independent legal advice on the modifications. Courts may scrutinize modifications more closely than original agreements to ensure neither party was pressured into changes.

Conclusion

Prenuptial agreements in New Brunswick provide couples with a powerful legal tool to customize their financial arrangements and protect individual interests before marriage. Under Section 34 of the Marital Property Act, properly executed marriage contracts allow spouses to opt out of the default 50/50 property division and establish their own terms for property division, spousal support, and other financial matters. The key to enforceability lies in meeting both formal requirements (written, signed, witnessed) and substantive standards (independent legal advice, full financial disclosure, fairness, and voluntary execution).

The investment of $1,500 to $5,000 in proper legal drafting provides significant protection against future disputes and the far greater costs of litigation. Given that Section 41 specifically empowers courts to override provisions when one party lacked independent legal advice, retaining separate lawyers for each party is not merely advisable—it is effectively essential for creating an enforceable agreement.

For couples considering a prenuptial agreement in New Brunswick, starting the process 3-6 months before the wedding ensures adequate time for thoughtful negotiation and documentation. The goal is not simply to have a signed document, but to create a fair agreement that both parties understand and accept, and that courts will uphold if ever challenged.