Disputes over prenuptial and postnuptial agreements arise when one party seeks to enforce the agreement as written while the other challenges its validity or the fairness of its terms. Common grounds for challenge include claims that the agreement was executed under duress or coercion, that one party failed to make full and fair disclosure of assets and liabilities, that the agreement was unconscionable at the time of execution, or that changed circumstances — such as the birth of children or significant shifts in wealth — render enforcement inequitable under applicable law.

In large-estate proceedings, these disputes are compounded by the interaction of the marital agreement with trust structures, business ownership interests, and estate plans that may have been established before, during, or after the marriage. Choice-of-law provisions within the agreement itself, or competing claims about which jurisdiction’s standards should govern enforceability, add further procedural complexity — particularly where the parties have maintained residences or business operations in multiple states or countries.

• Challenges to prenuptial agreements based on duress, undue influence, or coercion at the time of execution
• Claims of inadequate or fraudulent disclosure of assets in connection with the execution of marital agreements
• Unconscionability challenges — both procedural and substantive — under varying state standards
• Choice-of-law disputes over which jurisdiction’s enforcement standards apply to multi-state or international agreements
• Interaction of marital agreements with irrevocable trusts, closely held business interests, and multi-generational estate structures