Your prenup is a snapshot of your financial lives at a specific moment in time. But life doesn’t stand still. Careers change. Businesses grow or fail. Children arrive. Parents pass away and leave inheritances nobody anticipated. One partner gets a promotion that triples their income. The other decides to leave the workforce to raise kids. The agreement you signed before your wedding may no longer reflect your reality — and an outdated agreement can be worse than no agreement at all.
The good news: you can update it. And you should.
Can You Actually Change a Prenup After Marriage?
Yes. In Ontario, married couples can amend or replace their marriage contract at any time by creating a new agreement. The legal requirements are the same as the original: the amendment must be in writing, signed by both parties, and witnessed. Both partners should receive independent legal advice, and full financial disclosure should be updated to reflect current circumstances.
Think of it less like “changing” your prenup and more like creating a new version. Version 2.0. The amended agreement supersedes the original on any points where they differ, while the rest of the original remains intact.
This is actually a common practice. Lawyers report that couples who create prenups with built-in review schedules tend to have healthier financial partnerships overall, because they’re regularly checking in on their financial alignment.
When Should You Consider Updating?
There are several common life events that should trigger a prenup review:
Having children changes everything — especially if one partner reduces their career involvement to provide childcare. The financial impact of stepping away from the workforce for several years can be enormous: lost income, reduced pension contributions, career trajectory changes, and diminished earning capacity. A fair agreement should account for these sacrifices.
A major career change or income shift can also make an update necessary. If one partner’s income triples while the other’s stays flat, the original terms may no longer feel equitable. Similarly, starting or selling a business, receiving an inheritance, or purchasing a major asset like a second property should prompt a review. For more on how inheritances interact with prenups, see The Great Wealth Transfer: Why Your Inheritance Needs a Prenup.
Relocation is another critical trigger. If you move from Ontario to British Columbia, the provincial laws governing your marriage contract change. An agreement drafted for Ontario’s Family Law Act may not be fully enforceable under B.C.’s Family Law Act. A choice-of-law clause helps, but a full review is wise.
Other triggers include a significant change in health status, one partner returning to school, the couple taking on major joint debt, or the sale of a property that was addressed in the original agreement.
The Process of Amending
Amending a prenup follows the same principles as creating one. Both partners should disclose their current financial situation — which may look very different from when the original was signed. Both should discuss what changes they want and why. Both should have the opportunity to seek independent legal advice on the amended terms.
You can amend specific clauses while leaving the rest of the agreement intact, or you can create an entirely new agreement that replaces the original. The approach depends on how much has changed. For minor updates (adjusting a support figure, adding a new asset), a targeted amendment is usually sufficient. For major life overhauls, a fresh agreement may be cleaner and more enforceable.
What If Only One Partner Wants to Update?
Like the original agreement, any amendment requires mutual consent. One partner cannot unilaterally change the terms. If you believe the prenup should be updated but your partner disagrees, it may be worth having the conversation with the help of a mediator or therapist who specializes in couples’ financial discussions.
The key is framing the update as a shared benefit: “Our lives have changed, and I want our agreement to reflect where we are now — not where we were five years ago.” For guidance on navigating these conversations, see What Therapists Wish Couples Knew Before Signing a Prenup.
Build In a Review Schedule From the Start
The smartest approach is to include a review provision in your original prenup. Agree to revisit the terms every five years, or after specific milestones like the birth of a child, a significant asset acquisition, or a career change. This normalizes the review process and ensures neither partner is caught off guard by a request to amend. For more on these types of forward-looking features, read The “Sunset Clause” and Other Prenup Features Most People Don’t Know Exist.
Your prenup should grow with your marriage. Start or update yours at I Do Prenup.
Frequently Asked Questions
Q: Can I change my prenup without my spouse’s agreement?
No. Any amendment to a marriage contract requires mutual consent, written agreement, and proper execution (signatures and witnessing).
Q: Is an amended prenup as enforceable as the original?
Yes, as long as it meets the same legal requirements: in writing, signed by both parties, witnessed, with full financial disclosure.
Q: How often should we review our prenup?
Every five years is a good baseline, or after any major life event (children, career changes, property purchases, inheritances, or relocation to a different province).
Q: What if we move to a different province?
Your prenup may need to be reviewed for compliance with the new province’s family law. For a comparison of provincial rules, see Prenups Across Canada: How the Rules Change Province by Province.