Sunset Clauses in Prenuptial Agreements in New Brunswick: Complete 2026 Legal Guide

By Antonio G. Jimenez, Esq.New Brunswick17 min read

At a Glance

Residency requirement:
At least one spouse must have been habitually resident in New Brunswick for a minimum of one year immediately before filing the divorce petition, as required by section 3(1) of the Divorce Act. There is no requirement to be a Canadian citizen — you simply must have been physically and habitually living in the province for that period. There is no separate county or municipal residency requirement.
Filing fee:
$125–$225
Waiting period:
Child support in New Brunswick is calculated using the Federal Child Support Guidelines (SOR/97-175), which provide tables setting out monthly support amounts based on the paying parent's gross annual income and the number of children. In shared parenting time arrangements (where each parent has the child at least 40% of the time), the court may adjust support by considering both parents' incomes and the increased costs of maintaining two households. Special or extraordinary expenses — such as childcare, health insurance, or extracurricular activities — are shared between parents in proportion to their incomes.

As of June 2026. Reviewed every 3 months. Verify with your local clerk's office.

Need a New Brunswick divorce attorney?

One personally vetted attorney per county — by application only

Find Yours

A sunset clause in a New Brunswick prenuptial agreement is a contractual provision that automatically terminates the entire agreement, or specific terms within it, after a predetermined period such as 10, 15, or 20 years of marriage. Under New Brunswick's Marital Property Act, RSNB 2012, c. 107, marriage contracts containing sunset clauses are enforceable provided they meet the formal requirements of being in writing, signed by both parties, and witnessed. New Brunswick courts will uphold sunset clause prenup provisions unless applying the clause would be inequitable under Section 43 of the Marital Property Act, particularly if one spouse did not receive independent legal advice before signing.

Key Facts: Sunset Clause Prenups in New Brunswick

ElementNew Brunswick Requirement
Governing LawMarital Property Act, RSNB 2012, c. 107
Filing Fee (Divorce)$110 total ($100 petition + $10 clearance certificate)
Residency Requirement1 year in New Brunswick (Divorce Act, s. 3(1))
Independent Legal AdviceStrongly recommended; lack of ILA risks unenforceability
Typical Prenup Cost$2,500 to $6,000 for both spouses
Common Sunset Periods5, 7, 10, 15, or 20 years
Property Division Default50/50 marital property division

What Is a Sunset Clause Prenup in New Brunswick?

A sunset clause prenup New Brunswick couples sign contains an automatic expiration provision that renders the entire prenuptial agreement void after a specified marriage anniversary. Under New Brunswick law, couples may include language such as "This agreement shall terminate upon the tenth anniversary of the parties' marriage," which causes the prenup to expire completely on that date. The Marital Property Act, RSNB 2012, c. 107, Section 34 authorizes spouses to enter marriage contracts that define their property rights, and nothing in the Act prohibits time-limited provisions including sunset clauses.

New Brunswick recognizes two primary types of sunset clauses in prenuptial agreements. The first type terminates the entire agreement retroactively, meaning all property reverts to standard provincial division rules as if no prenup existed. The second type phases out specific provisions gradually, such as reducing spousal support waivers by 10% for each year of marriage until complete elimination at year 10. Courts generally enforce both types when the language is unambiguous and both parties received independent legal advice.

The prenup expiration date matters significantly in divorce proceedings. If spouses separate before the sunset date but finalize their divorce after it passes, New Brunswick courts will likely treat the prenup as expired based on the date the marriage legally ended, not when separation occurred. This principle follows contract law interpretation, where the plain meaning of "marriage anniversary" refers to the legal status of being married, not cohabitation.

How New Brunswick Law Governs Prenuptial Agreement Sunset Clauses

New Brunswick's Marital Property Act, RSNB 2012, c. 107 establishes the legal framework governing all domestic contracts, including prenuptial agreements with sunset clauses. Section 34 of the Act permits spouses to enter marriage contracts that address property division, spousal support, and other financial matters during marriage, upon separation, or at death. The Act does not impose a mandatory duration on marriage contracts, meaning couples retain complete discretion to include prenup duration limits of 5, 10, 20 years, or any other timeframe.

Under Section 43 of the Marital Property Act, a court may disregard any provision of a domestic contract, including a sunset clause, if: (a) the contract was made before the Marital Property Act came into force without contemplating the Act; or (b) the spouse challenging the provision entered the agreement without receiving independent legal advice. The court applies this power only when it determines that enforcing the provision would be inequitable in all circumstances of the case. This dual requirement of inadequate legal advice plus inequitable outcome means properly drafted sunset clauses with independent legal advice for both parties face minimal court interference.

The federal Divorce Act, R.S.C. 1985, c. 3 governs divorce proceedings and interacts with provincial marriage contracts. When spouses divorce before a sunset clause activates, the prenuptial terms apply in full to property division and spousal support. If divorce occurs after the sunset date, the marriage contract no longer binds the parties, and New Brunswick's default 50/50 marital property division under the Marital Property Act applies automatically.

Common Sunset Clause Timeframes and Their Implications

New Brunswick couples drafting prenuptial agreements typically select sunset periods ranging from 5 to 25 years based on their specific circumstances and risk tolerance. The 5-to-7-year prenup years married threshold appeals to couples where one spouse has significantly greater wealth entering the marriage and wants protection during the initial establishment period. The 10-to-15-year range represents the most common time limit prenup choice, balancing asset protection with recognition that long-term marriages merit shared financial outcomes. Sunset clauses of 20 years or longer provide maximum protection while still acknowledging that decades-long unions should trigger standard provincial property rules.

Sunset PeriodTypical Use CaseRisk Level
5 yearsShort-term protection, second marriagesHigh (prenup expires quickly)
7 yearsInitial marriage trial periodMedium-High
10 yearsStandard protection, balanced approachMedium
15 yearsExtended protection, complex assetsMedium-Low
20+ yearsMaximum protection, high-net-worth couplesLow

Partial sunset clauses allow couples to create hybrid arrangements where only certain provisions expire while others remain indefinitely. For example, a New Brunswick prenup might specify that the spousal support waiver expires after 10 years of marriage, but the separate property designation for pre-marital assets continues permanently. This prenup expiration structure acknowledges that financial interdependence increases over time while still protecting assets acquired before marriage.

Event-based sunset clauses tie prenup expiration to life milestones rather than calendar dates. Common triggering events include the birth of a first child, one spouse achieving a specified net worth, or completion of professional education. New Brunswick courts treat event-based clauses identically to time-based ones, enforcing them if the triggering event is clearly defined and ascertainable.

Drafting Requirements for Enforceable Sunset Clauses in New Brunswick

A sunset clause prenup New Brunswick courts will enforce must satisfy both formal validity requirements under the Marital Property Act and substantive fairness standards. The agreement must be in writing, signed by both parties, and witnessed by at least one individual who observes both signatures. While the Act does not mandate notarization, having the agreement notarized adds an additional layer of authentication that can strengthen enforceability.

Clear and unambiguous language is essential for sunset clause validity. The provision should state the exact date or event triggering expiration, whether expiration is retroactive or prospective, which provisions expire if not the entire agreement, and what legal framework applies after expiration. Sample language meeting these requirements: "This Agreement shall terminate in its entirety on the fifteenth anniversary of the marriage date, at which time all rights and obligations created herein shall cease and the parties' property rights shall be governed by the Marital Property Act, RSNB 2012, c. 107."

Independent legal advice for both parties represents the single most important factor in sunset clause enforceability. Under Section 43 of the Marital Property Act, courts may disregard provisions when one spouse lacked independent counsel and enforcement would be inequitable. Each spouse should retain a separate family lawyer who reviews the entire agreement, explains the sunset clause implications, confirms understanding of rights being waived, and provides a certificate of independent legal advice. The cost of two lawyers ($2,500 to $6,000 total) represents a small investment compared to the millions of dollars potentially at stake in a divorce without an enforceable prenup.

Full financial disclosure must accompany any prenuptial agreement. Both spouses should attach net worth statements listing all assets, liabilities, income sources, and business interests. Failure to disclose material assets can invalidate the entire agreement, not just the sunset clause, because courts view concealment as fundamentally incompatible with the voluntary, informed consent required for contract enforcement.

Modifying or Removing a Sunset Clause Before It Triggers

New Brunswick law permits spouses to amend their marriage contract at any time through a subsequent written agreement meeting the same formal requirements as the original. If both parties agree that the sunset clause no longer reflects their intentions, they can execute an amendment extending the sunset date, removing the sunset clause entirely, converting a complete expiration to a partial one, or replacing the existing prenup with an entirely new postnuptial agreement. Each modification requires independent legal advice to ensure enforceability.

As a sunset date approaches, couples should evaluate their options at least 12 to 24 months before expiration. This timeline allows adequate time for financial analysis, lawyer consultations, negotiations, and proper documentation. Waiting until the final months creates pressure that could later be characterized as coercion, potentially undermining the amended agreement's validity.

Unilateral modification is not possible under New Brunswick law. If one spouse wants to eliminate the sunset clause but the other refuses, the original provision remains binding. Courts will not rewrite agreed-upon terms simply because one party later regrets the deal. The only remedy is formal renegotiation or allowing the sunset clause to activate as originally drafted.

What Happens When a Prenup Sunset Clause Activates

When a prenuptial agreement sunset clause activates in New Brunswick, the marriage contract becomes null and void from that date forward. The legal effect depends on whether the clause is retroactive or prospective. A retroactive sunset clause treats all property as if no prenup ever existed, subjecting the entire marital estate to 50/50 division under the Marital Property Act. A prospective sunset clause only terminates future application, preserving any property divisions or designations that occurred before expiration.

Spouses remain legally married after a sunset clause activates, but their property rights shift to provincial default rules. Under New Brunswick's Marital Property Act, marital property includes all assets acquired during the marriage by either spouse, while pre-marital property may remain exempt depending on how it was maintained and whether its value increased during marriage. Without an enforceable prenup, courts apply equitable distribution principles that typically result in near-equal division.

Spousal support obligations follow a similar pattern. If the expired prenup contained a spousal support waiver, that waiver no longer applies after the sunset date. Either spouse may then claim spousal support under the federal Divorce Act, R.S.C. 1985, c. 3, Section 15.2 based on need, ability to pay, and the standard of living during marriage. Courts assess support claims without reference to the expired waiver, applying the Spousal Support Advisory Guidelines as they would in any divorce without a prenuptial agreement.

Parenting Arrangements Cannot Be Affected by Sunset Clauses

Under New Brunswick law and the federal Divorce Act, R.S.C. 1985, c. 3, as amended in 2021, no prenuptial agreement, including those with sunset clauses, can predetermine parenting arrangements for children. Section 34(d) of the Marital Property Act explicitly prohibits marriage contracts from addressing parenting time or decision-making responsibility. Courts must determine these matters based solely on the best interests of the child at the time of separation, not according to contractual terms signed years earlier.

The 2021 amendments to Canada's Divorce Act replaced the former terms "custody" and "access" with "parenting time" and "decision-making responsibility." Parenting time refers to when a child is in the care of each parent, while decision-making responsibility covers major decisions about education, health care, religion, and extracurricular activities. These allocations depend on factors including each parent's ability to care for the child, the child's relationship with each parent, any history of family violence, and the child's own views if age-appropriate.

Sunset clauses in prenuptial agreements therefore have no bearing on parenting-related matters. Even if a prenup states that one parent will have primary parenting time, New Brunswick courts will ignore such provisions entirely. This limitation means that couples cannot use sunset clauses to "phase in" parenting arrangements over time or condition parenting allocation on the duration of the marriage.

Costs of Creating a Sunset Clause Prenup in New Brunswick

Creating an enforceable prenuptial agreement with a sunset clause in New Brunswick typically costs between $2,500 and $6,000 total when both spouses retain separate lawyers, with each party paying approximately $1,500 to $3,000 for drafting and independent legal advice. Family lawyers in New Brunswick generally charge between $250 and $450 per hour for prenuptial agreement work, with total hours depending on asset complexity, negotiation rounds required, and sunset clause sophistication.

Cost ComponentTypical Range
Drafting lawyer (Party A)$1,500 to $3,000
Reviewing lawyer (Party B)$800 to $1,500
Notarization (optional)$50 to $150
Financial disclosure preparation$200 to $500
Amendments/modifications$500 to $1,500 each
Total typical cost$2,500 to $6,000

Online prenuptial agreement services available to Canadian residents cost between $429 and $1,500, representing 50% to 80% savings compared to traditional lawyer-drafted agreements. However, these template-based services may not adequately address New Brunswick-specific requirements under the Marital Property Act or create properly enforceable sunset clauses. Courts scrutinize template agreements more heavily, particularly when one spouse claims they did not understand the sunset clause implications.

The return on investment for a properly drafted prenup far exceeds the initial cost. Divorce litigation in New Brunswick typically costs $15,000 to $50,000 per spouse for contested property disputes. An enforceable prenuptial agreement with clear sunset provisions eliminates most property litigation, potentially saving couples $30,000 to $100,000 in legal fees while providing certainty about financial outcomes regardless of when separation occurs relative to the sunset date.

When to Consider Including a Sunset Clause

Sunset clauses benefit New Brunswick couples where significant wealth disparity exists at marriage but both parties expect that gap to narrow over time. The wealthier spouse gains initial protection while the less wealthy spouse knows the prenup has a defined end date. This structure addresses concerns about "marrying for money" during the early marriage years while acknowledging that decades-long partnerships create genuine economic partnership.

Second marriages often include sunset clauses to balance competing obligations. A spouse entering a second marriage may have children from the first marriage, existing spousal support obligations, or family business interests requiring protection. A 10-year sunset clause protects these pre-existing obligations while recognizing that the new marriage, if it endures beyond a decade, merits financial recognition.

Younger couples with limited current assets but high earning potential represent another group benefiting from sunset clauses. A couple marrying in their mid-20s with few assets may want protection for anticipated inheritances or business ventures, but also recognize that their circumstances will change dramatically over 15 or 20 years. A sunset clause allows asset protection during the wealth-building years while ensuring that truly long-term marriages receive different treatment.

Conversely, sunset clauses may disadvantage spouses who sacrifice career development for family responsibilities. A spouse who leaves the workforce to raise children for 15 years may find that the sunset clause activated just as the marriage ended, leaving them without the spousal support waiver that would have applied had divorce occurred a year earlier. Careful consideration of life plans and potential scenarios should precede any sunset clause decision.

Frequently Asked Questions

Are sunset clause prenups legally enforceable in New Brunswick?

Yes, sunset clause prenups are legally enforceable in New Brunswick when they comply with the formal requirements of the Marital Property Act, RSNB 2012, c. 107. The agreement must be in writing, signed by both parties, and witnessed. Courts will uphold sunset clauses unless one spouse lacked independent legal advice and enforcement would be inequitable under Section 43.

What happens if we divorce after the sunset clause has expired?

When divorce occurs after a sunset clause has expired, New Brunswick's default property division rules under the Marital Property Act apply in full. The prenuptial agreement no longer binds either party, meaning marital property divides approximately 50/50 and spousal support claims proceed without reference to any waivers in the expired agreement.

Can we extend or remove a sunset clause before it activates?

Yes, spouses may amend their marriage contract at any time before the sunset clause activates by executing a written modification that both parties sign and witness. Each spouse should obtain independent legal advice on the amendment. Courts enforce modifications meeting the same formal requirements as the original prenup.

How do sunset clauses interact with spousal support waivers?

Spousal support waivers contained in a prenuptial agreement expire along with the sunset clause unless the agreement specifies otherwise. After expiration, either spouse may claim spousal support under the Divorce Act, R.S.C. 1985, c. 3, Section 15.2 based on entitlement factors including length of marriage and economic consequences of separation.

What is the most common sunset clause duration in New Brunswick prenups?

The 10-year prenup duration represents the most commonly selected sunset period in New Brunswick prenuptial agreements. This timeframe balances asset protection during the marriage establishment phase with recognition that decade-long unions create meaningful economic partnership and aligns with federal support guidelines.

Can a prenup sunset clause affect parenting arrangements?

No, prenuptial agreement sunset clauses cannot affect parenting arrangements under New Brunswick law. The Marital Property Act, Section 34(d) prohibits marriage contracts from addressing parenting time or decision-making responsibility. Courts determine all parenting matters based solely on the child's best interests at separation.

Do I need a lawyer to create a prenup with a sunset clause in New Brunswick?

While not technically required, obtaining independent legal advice for both parties is practically essential for enforceability. Under Section 43 of the Marital Property Act, courts may disregard provisions when one spouse lacked independent counsel and enforcement would be inequitable. Budget $2,500 to $6,000 total for two lawyers.

What happens to separate property when a sunset clause expires?

When a sunset clause expires, the prenuptial agreement's property designations cease to apply. Assets previously classified as separate property become subject to New Brunswick's default rules under the Marital Property Act. Property owned before marriage generally remains exempt, but appreciation during marriage may be divisible.

Can we include partial sunset clauses that affect only some provisions?

Yes, New Brunswick law permits partial sunset clauses that terminate specific provisions while maintaining others indefinitely. For example, a prenup might specify that spousal support waivers expire after 10 years while separate property designations continue permanently. Partial sunset clauses require precise drafting.

How far in advance of the wedding should we finalize a sunset clause prenup?

New Brunswick family lawyers recommend finalizing prenuptial agreements with sunset clauses at least 30 to 60 days before the wedding. This timeline ensures adequate opportunity for independent legal advice, financial disclosure, and negotiation without time pressure that could later be characterized as coercion.

Estimate your numbers with our free calculators

View New Brunswick Divorce Calculators

Written By

Antonio G. Jimenez, Esq.

Florida Bar No. 21022 | Covering New Brunswick divorce law

Vetted New Brunswick Divorce Attorneys

Each city on Divorce.law has one personally vetted exclusive attorney.

+ 1 more New Brunswick cities with exclusive attorneys

Part of our comprehensive coverage on:

Prenuptial Agreements — US & Canada Overview