Hawaii: Prenuptial Agreement Requirements

Requirements one by one

Hawaii uses the Uniform Premarital Agreement Act

HRS § 572D-11 names the Uniform Premarital Agreement Act, and HRS § 572D-1
defines the agreement as one between prospective spouses made in contemplation
of marriage and intended to become effective upon marriage.

The current operative sections remain the 1987 enactment. HRS § 572D-10
separately preserves pre-July 1, 1987 written agreements when they are otherwise
valid contracts.

Both parties must sign a writing

HRS § 572D-2 requires the agreement to be in writing and signed by both parties.
It is enforceable without consideration, so no separate payment or property
exchange is required.

Signing does not itself activate the agreement. Under HRS § 572D-4, the
agreement becomes effective when the parties marry each other.

Chapter 572D adds no notary or witness rule

The statutory form is the writing signed by both parties. Chapter 572D does not
add notarization, acknowledgment, witnesses, attestation, an oath, or recording
as a general validity requirement for the prenup itself.

Separate deeds, trusts, beneficiary designations, or other instruments used to
carry out a term can have their own formalities. Those do not become universal
prenup requirements under § 572D-2.

Disclosure is part of a combined defense

HRS § 572D-6(a)(2) 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 by itself does
not complete this defense if a qualifying written waiver or adequate knowledge
defeats another required element.

Counsel and timing are voluntariness factors

Chapter 572D does not require separate lawyers, a written counsel-waiver form,
a fixed final-draft review period, or signing a stated number of days before the
wedding.

LO v. NO. adopted a practical voluntariness test for Hawaii prenups. Courts
should consider wedding proximity or surprise, counsel or an opportunity to
consult counsel, bargaining power and sophistication, disclosure, and the
parties' understanding of the rights waived or the agreement's purpose.

The statutory enforcement routes are distinct

HRS § 572D-6 makes involuntary execution sufficient by itself to defeat
enforcement. The alternative route requires unconscionability when the
agreement was executed together with all three disclosure failures.

The court decides unconscionability as a matter of law. Chapter 572D does not
state a general enforcement-time unconscionability or changed-circumstances
review for every term.

Support terms have a public-assistance floor

HRS § 572D-3(a)(4) permits modification or elimination of spousal support.
Section 572D-6(b) 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 broader enforcement-time hardship rewrite of
every support waiver.

Child support and custody remain protected

HRS § 572D-3(b) 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. HRS § 571-46(a)(1) directs the court to
award custody to one or both parents according to the child's best interests.

Later changes require a signed writing

Under HRS § 572D-5, amendment or revocation after marriage requires a written
agreement signed by both parties. The amendment or revocation is enforceable
without consideration.

The section does not add notarization, witnesses, or another acknowledgment
step. A form should not label notarization of every amendment as a chapter 572D
requirement.

What trips people up

• The signing date is not the effective date. Section 572D-4 activates the
  agreement upon marriage.
• The disclosure route is conjunctive. Execution-time unconscionability and
  all three disclosure failures must appear together.
• A same-day signing is not automatically invalid. LO makes wedding
  proximity one factor within the full voluntariness inquiry.

Common questions

Does a Hawaii prenup need to be notarized?

No general notary requirement appears in chapter 572D. HRS § 572D-2 states the
form as a writing signed by both parties.

Must each person hire a separate lawyer?

The Act does not make actual separate representation a formal prerequisite.
LO v. NO. treats counsel or a real opportunity to consult counsel as one of the
factors in deciding whether execution was voluntary.

What if the marriage is declared void?

Under HRS § 572D-7, an agreement that otherwise would have been a prenup is
enforceable only to the extent necessary to avoid an inequitable result. HRS
§ 572D-8 tolls limitations during marriage while preserving equitable defenses
such as laches and estoppel.

Statutes and sources

• HRS chapter 572D — Hawaii Uniform Premarital Agreement Act: definition,
  form, content, effect, amendment, enforcement, and older agreements.
  Official Hawaii Legislature
  page
  (accessed 2026-07-28).
• HRS § 571-46(a)(1) — custody according to the child's best interests.
  Official Hawaii Legislature
  page
  (accessed 2026-07-28).
• LO v. NO., 148 Hawaiʻi 336 (2020) — voluntariness factors for premarital
  agreements under HRS § 572D-6. Opinion
  (accessed 2026-07-28).