UPAA vs Non-UPAA States — How Prenup Enforceability Differs
The baseline rule most states share, and where case-law states differ.
What the UPAA Does
The Uniform Premarital Agreement Act gives adopting states a shared rule: a prenup is valid if it is in writing and signed voluntarily by both people before marriage, with fair disclosure of assets and debts (or a clear, knowing waiver of that disclosure). Most U.S. states have adopted it, which is why prenup formalities look similar across most of the country.
Where Case-Law States Differ
States that did not adopt the UPAA, such as New York, enforce prenups through their own court decisions. The core ideas are the same (writing, voluntary signing, disclosure, no fraud or duress), but the exact tests and formalities come from case law, so the details can differ. Use the state pages on this site to compare.
A Shared Bottom Line
Regardless of UPAA status, a prenup is far more likely to hold up if both parties have their own lawyer, disclose finances fully, sign well before the wedding, and avoid any pressure. This is general information, not legal advice.
Laws change and states apply them differently. Confirm current rules with a licensed attorney in the relevant state.
Frequently Asked Questions
What is the Uniform Premarital Agreement Act (UPAA)?
The UPAA is a model law adopted by most U.S. states. It sets a simple baseline: a prenup must be in writing and signed voluntarily by both parties. Most adopting states also require fair financial disclosure or a knowing waiver of it.
Which states do not follow the UPAA?
A few states, most notably New York, do not follow the UPAA and instead rely on their own case law. There, prenups must still be in writing and signed voluntarily, but the details of enforceability come from court decisions rather than the uniform statute.