Idaho Prenuptial Agreement Laws: Requirements and Enforceability

Yes, a prenuptial agreement can be enforceable in Idaho. Idaho has adopted the Uniform Premarital Agreement Act, Idaho Code 32-921 to 32-929, which requires a written agreement signed by both parties and sets out in section 32-925 when a court will refuse to enforce one.

Information last verified on 2026-10-08. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers premarital (prenuptial) agreements under Idaho's Uniform Premarital Agreement Act, Idaho Code 32-921 to 32-929, with a note on community property division under Idaho Code 32-712. It does not cover postnuptial agreements, Idaho case law on premarital agreements, or other states' law. It is general information, not drafting guidance; a lawyer licensed in Idaho can draft or review these agreements.

Which Idaho law governs prenuptial agreements

Idaho's statute is the Uniform Premarital Agreement Act, Idaho Code 32-921 to 32-929, in Title 32, chapter 9. Section 32-929 provides: "This act may be cited as the 'Uniform Premarital Agreement Act.'"

Idaho added the Act in 1995 (1995 Idaho Sess. Laws ch. 229), and the codified sections do not state which agreements it applies to by date. A lawyer licensed in Idaho can say which rules govern an older agreement.

Formal requirements for an Idaho prenup

Section 32-922 sets the formalities:

"A premarital agreement must be in writing and signed by both parties. It is enforceable without consideration. The premarital agreement shall be executed and acknowledged or proved as provided in sections 32-917 through 32-919, Idaho Code."

Three points follow from that text. An oral prenup does not meet the statute. No payment or other consideration is needed. And beyond signing, the agreement must be executed and acknowledged or proved in the manner that sections 32-917 through 32-919 provide. Section 32-917 requires marriage settlements to be executed and acknowledged or proved in the same manner as a conveyance of land.

When an Idaho prenup is not enforceable

Section 32-925(1) gives two routes for a party resisting the agreement.

Involuntariness. The agreement is not enforceable if "That party did not execute the agreement voluntarily."

Unconscionability plus lack of disclosure. The agreement is also unenforceable if it "was unconscionable when it was executed" and, before signing, that party:

• "Was not provided a fair and reasonable disclosure," as the statute describes it,
• did not voluntarily and expressly waive, in writing, any right to disclosure beyond the disclosure provided, and
• did not have, or reasonably could not have had, adequate knowledge of the other party's property or financial obligations.

All of those conditions run together on this route: unconscionability at signing combined with the disclosure failures. Under section 32-925(3), whether an agreement is unconscionable is decided by the court as a matter of law.

The Act's sections cited here do not set a separate requirement that each party have independent counsel, or a waiting period between signing and the wedding.

Spousal support waivers in Idaho

A premarital agreement can address spousal support, but section 32-925(2) sets a limit tied to public assistance: "a court, notwithstanding the terms of the agreement, may require the other party to provide support to the extent necessary to avoid that eligibility." The eligibility it refers to is a spouse's eligibility for public assistance.

For how spousal support works without an agreement, see Idaho alimony laws.

What an Idaho prenup cannot do

Child support. Idaho Code 32-923(2) provides: "The right of a child to support may not be adversely affected by a premarital agreement." Parents cannot use a prenup to reduce what a child is owed.

This page does not cover whether or how a premarital agreement can address child custody in Idaho.

Changing or revoking an Idaho prenup

Section 32-924 provides: "After marriage, a premarital agreement may be amended or revoked only by a written agreement signed by the parties. The amended agreement or the revocation is enforceable without consideration."

Time limits are paused while the marriage lasts. Under section 32-927, "Any statute of limitations applicable to an action asserting a claim for relief under a premarital agreement is tolled as to the premarital agreement during the marriage of the parties." The same section adds that "equitable defenses limiting the time for enforcement, including laches and estoppel, are available to either party," so delay can still matter.

Postnuptial agreements in Idaho

This page does not cover agreements made after the wedding. The rules above come from the premarital agreement act, and this page does not cover an Idaho statute or case on postnuptial agreements. A lawyer licensed in Idaho can explain how an agreement signed during marriage is treated.

Idaho community property and prenups

Idaho is a community property state. Title 32, chapter 9 covers husband and wife and separate and community property, and on divorce Idaho Code 32-712 provides: "Unless there are compelling reasons otherwise, there shall be a substantially equal division in value, considering debts, between the spouses." Under the same section, an antenuptial agreement is a factor the court considers, and the court cannot amend or rescind it.

For how property is divided in an Idaho divorce, see Idaho divorce laws.

Disclaimer: This article provides general legal information about premarital agreements under Idaho's Uniform Premarital Agreement Act, Idaho Code 32-921 to 32-929. It is not legal advice and is not a template. The information was verified on 2026-10-08, and the law can change. For advice about your situation, consult a lawyer licensed in Idaho.

Related

• Prenuptial agreement laws in every state
• Idaho divorce laws
• Idaho alimony laws

Last updated: 2026-10-08.

Frequently Asked Questions

Are prenups enforceable in Idaho?

Generally yes, under the Uniform Premarital Agreement Act, Idaho Code 32-921 to 32-929. Section 32-925 makes an agreement unenforceable if a party did not sign voluntarily, or if it was unconscionable when signed and the disclosure conditions in that section are met.

Does a prenup have to be notarized in Idaho?

Idaho Code 32-922 requires the agreement to be in writing, signed by both parties, and executed and acknowledged or proved as provided in sections 32-917 through 32-919. Section 32-917 requires marriage settlements to be executed and acknowledged or proved in the same manner as a conveyance of land.

Can a prenup waive alimony in Idaho?

An agreement can address spousal support, but under Idaho Code 32-925(2) a court may still require support to the extent necessary to keep a spouse from becoming eligible for public assistance.

Can a prenup limit child support in Idaho?

No. Idaho Code 32-923(2) provides that a child's right to support may not be adversely affected by a premarital agreement.

Can you change a prenup after the wedding in Idaho?

Yes, but only by a written agreement signed by the parties, under Idaho Code 32-924. The amendment or revocation is enforceable without consideration.