Many people who are planning to get married enter into prenuptial agreements, also known as premarital agreements or, more casually, prenups. While prenuptial agreements were once used primarily by people with significant wealth, soon-to-be spouses of all socioeconomic backgrounds now rely on them to resolve certain financial issues in the event of a divorce.
Over the last two decades, the American Academy of Matrimonial Lawyers (AAML) has seen a fivefold rise in the use of prenups, particularly among millennials. If you do enter into a prenuptial agreement, you might be wondering how long it will last and whether or not it will be effective in the event of a divorce.
While it is important to consider specific state laws that govern prenups, these agreements are generally designed to last the length of a marriage unless the prenup is unenforceable under state law. However, there are some exceptions.
Prenuptial Agreements Usually Last Until Divorce
Prenuptial agreements typically last until the parties to the agreement end their marriage with a divorce. Since these types of agreements are used to clarify financial issues in the event of a divorce, spouses usually enter into a prenuptial agreement with the assumption that the agreement will be in force until a divorce. If the parties never get divorced, any terms within the prenuptial agreement will most often remain in force throughout the length of the marriage.
Expiration Dates on Prenups
While most prenuptial agreements do last for the entire length of a marriage, there are some prenups that include an expiration date, or a “sunset clause.” A sunset clause is a clause in a contract that says the terms of the agreement will terminate after a specific amount of time passes.
In some cases, couples include a sunset clause in a prenuptial agreement to set an expiration date for the terms within the prenup. For instance, a sunset clause in a premarital agreement might say that the terms expire once the marriage has lasted 5, 10, or 20 years.
While sunset clauses or expiration dates in prenuptial agreements are uncommon, they may be possible in a number of states.
Considering the Enforceability of Prenuptial Agreements
Even when a prenup is designed to last the length of a marriage, it is important to consider whether the contract is actually enforceable. Most states make clear that prenuptial agreements can be unenforceable for a variety of reasons, such as:
- The agreement was signed while one of the parties was under duress
- One of the spouses provided fraudulent information to the other in order to get the prenup signed
- Certain terms of the prenuptial agreement are unconscionable
When the terms of a prenup are unenforceable under state law, the agreement will not last the length of the marriage—or any other term specified in the document—in practice. If you have questions or concerns, you should contact a family law attorney in your state.

