Idaho: Prenuptial Agreement Requirements

Requirements one by one

Idaho uses the Uniform Premarital Agreement Act

Idaho Code §§ 32-921 to 32-929 are Idaho's Uniform Premarital Agreement Act;
Idaho Code § 32-929 supplies the short title. Idaho Code § 32-921(1) defines
the agreement as one between prospective spouses, made in contemplation of
marriage and intended to become effective upon marriage.

Idaho links the Act to older marriage-settlement provisions. That cross-
reference adds acknowledgment or proof and a real-estate recording rule beyond
the basic uniform signed-writing requirement.

The agreement needs writing, signatures, and acknowledgment or proof

Idaho Code § 32-922 requires a writing signed by both parties and makes it
enforceable without consideration. It then requires the agreement to be
executed and acknowledged or proved under §§ 32-917 to 32-919.

Section 32-917 describes the comparison directly: marriage settlements must be
executed and acknowledged or proved in the same manner as land conveyances.
Under § 51-102(1), an acknowledgment is a declaration before a notarial officer
that the individual signed the record for its stated purpose.

Real-estate terms trigger county recording

Idaho Code § 32-918 governs the filing step. If the agreement grants or affects
real estate, it must be recorded in every county where that real estate is
situated. A signed and acknowledged statutory summary may be recorded in place
of the full agreement. Idaho Code § 32-919 gives recording or nonrecording the
same effect as for a real-property conveyance.

Recording and nonrecording have the same effect as for a real-property
conveyance. Idaho Code § 55-815 says an unrecorded instrument remains valid
between its parties and people who have notice, which distinguishes the
recording consequence from the initial acknowledgment-or-proof requirement.

Disclosure is part of a combined defense

Section 32-925(1)(b) requires execution-time unconscionability and all three
listed disclosure failures: no fair and reasonable disclosure, no voluntary
express written waiver of additional disclosure, and no actual or reasonably
available adequate knowledge.

The requirements are conjunctive. A missing financial schedule alone does not
complete the statutory defense if a qualifying written waiver or adequate
knowledge defeats another required element.

The Act sets no counsel or wedding countdown

The Act does not require separate lawyers, a written counsel advisement or
waiver, a final-draft review period, or signing a fixed number of days before
the wedding.

Voluntary execution remains an independent condition under § 32-925(1)(a).
The absence of a numerical waiting period does not remove the court's inquiry
into whether the actual execution was voluntary.

The enforcement routes are distinct

Idaho Code § 32-925 supplies two routes to nonenforcement. Involuntary execution
is sufficient by itself. The alternative requires unconscionability when the
agreement was executed together with all three disclosure failures.

The court decides unconscionability as a matter of law. The section does not
state a general enforcement-time unconscionability or changed-circumstances
review for every provision.

Support terms have a public-assistance floor

Idaho Code § 32-923(1)(d) permits modification or elimination of spousal
support. Section 32-925(2) supplies a targeted override if that term causes
public-assistance eligibility at separation or dissolution: the court may order
enough support to avoid the eligibility.

The statute does not create a general fairness rewrite of every support waiver
at enforcement.

Child support and custody remain protected

Section 32-923(2) says a prenup may not adversely affect a child's right to
support. Personal-rights terms also may not violate public policy or a statute
imposing a criminal penalty.

Custody remains a later court decision. Idaho Code § 32-717(1) directs the court
to make custody, care, and education orders that appear necessary or proper in
the children's best interests.

Later changes require a signed writing

Under Idaho Code § 32-924, amendment or revocation after marriage requires a
written agreement signed by both parties and is enforceable without
consideration.

The amendment sentence does not repeat § 32-922's acknowledgment-or-proof
language or state a new notary requirement. A form should not describe
notarization of every later amendment as a requirement stated in § 32-924.

What trips people up

• Both signatures are not the whole execution rule. Section 32-922 also
  incorporates acknowledgment or proof under the marriage-settlement statutes.
• Real-estate terms can require recording in multiple counties. The filing
  follows each affected parcel, not simply the county where the spouses live.
• The disclosure defense is conjunctive. Execution-time
  unconscionability and all three disclosure failures must appear together.

Common questions

Does an Idaho prenup need a notary?

The initial agreement must be acknowledged or proved like a land conveyance.
An acknowledgment is made before a notarial officer, which includes a notary
public or another person authorized to perform notarial acts. Section 32-922
also preserves the statutory proof alternative.

Must every Idaho prenup be recorded?

Section 32-918's express recording command applies when the marriage settlement
grants or affects real estate. It requires recording in every county where the
affected property is situated and permits a qualifying summary instead of the
full contract.

What if the marriage is declared void?

Under Idaho Code § 32-926, an agreement that otherwise would have been a prenup
is enforceable only to the extent necessary to avoid an inequitable result.
Idaho Code § 32-927 tolls limitations during marriage while preserving
equitable time defenses such as laches and estoppel.

Statutes and sources

• Idaho Code §§ 32-921 to 32-929 — Uniform Premarital Agreement Act:
  definition, form, content, effect, later changes, enforcement, and void-
  marriage treatment. Official Idaho Legislature
  page
  (accessed 2026-07-28).
• Idaho Code §§ 32-917 to 32-919 — acknowledgment or proof and recording
  rules incorporated into the prenup formality section. Official Idaho
  Legislature page
  (accessed 2026-07-28).
• Idaho Code § 51-102 — acknowledgment and notarial-officer definitions.
  Official Idaho Legislature
  page
  (accessed 2026-07-28).
• Idaho Code § 55-815 — effect of an unrecorded instrument between parties
  and people with notice. Official Idaho Legislature
  page
  (accessed 2026-07-28).
• Idaho Code § 32-717(1) — custody orders based on the child's best
  interests. Official Idaho Legislature
  page
  (accessed 2026-07-28).