Couples who skipped a prenup before the wedding sometimes find themselves wanting similar protections years into the marriage — after a business gets started, an inheritance arrives, or trust needs rebuilding after a rocky patch. That’s where a postnuptial agreement comes in, and naturally, the next question is whether it’s something you can draft yourselves without paying attorney fees. Technically, yes. Practically, it’s one of the riskier documents to attempt alone.
What a Postnuptial Agreement Actually Does
A postnuptial agreement, often shortened to “postnup,” is a legal contract signed after marriage that spells out how assets, debts, and sometimes support obligations will be handled if the marriage ends in divorce or death. It functions similarly to a prenuptial agreement, just executed later, and can cover things like:
- Division of property acquired during the marriage
- Protection of separate assets, such as an inheritance or a business started before or during the marriage
- Spousal support terms in the event of divorce
- Debt responsibility, particularly important if one spouse is taking on significant new financial risk
- Estate planning coordination, especially in blended families with children from previous relationships
Is It Legal to Write One Without an Attorney?
Yes, nothing in the law requires a postnuptial agreement to be drafted or reviewed by an attorney. Courts don’t reject these agreements simply because a lawyer wasn’t involved. The real issue isn’t legality — it’s enforceability, and that’s where DIY postnups run into serious trouble.
Why Enforceability Is the Real Challenge
Courts scrutinize postnuptial agreements more closely than most other contracts, precisely because they’re signed between people who already have significant legal obligations to one another. A judge reviewing a postnup later, often during a contentious divorce, will typically look for:
- Full financial disclosure. Both spouses must have honestly disclosed their complete financial picture before signing — hidden assets or debts can void the entire agreement.
- Voluntary signing. The agreement must be entered into freely, without coercion, pressure, or one spouse threatening divorce to force a signature.
- Fair and reasonable terms. Courts in many states will strike down agreements that are excessively one-sided or unconscionable at the time of signing or enforcement.
- Proper execution. Requirements like notarization, witnesses, or specific formatting vary by state, and a document that skips these steps can be thrown out on a technicality alone.
- Independent understanding. Some states expect evidence that each spouse actually understood what they were signing, which is much harder to demonstrate without separate legal counsel involved.
A postnup that fails on any of these fronts can be invalidated entirely, meaning the couple spent time and effort creating a document that offers zero protection when it’s actually needed.
Where DIY Postnups Commonly Fall Apart
Couples attempting this without legal guidance tend to run into the same handful of problems:
- Using vague or generic template language that doesn’t reflect their specific state’s requirements
- Failing to fully disclose all assets and debts, sometimes unintentionally, which can undermine the entire agreement later
- Not accounting for how state law treats certain assets differently, such as retirement accounts or jointly titled property
- Overlooking required formalities like notarization or specific witness requirements that vary significantly by state
- Writing terms so favorable to one spouse that a court later deems the agreement unconscionable
When a DIY Approach Might Be Reasonable
Not every postnup situation demands full attorney representation on both sides. A simpler approach might be defensible when:
- The couple’s finances are straightforward, with minimal assets, no business interests, and no children from previous relationships
- Both spouses are in complete agreement and simply want to formalize an understanding they’ve already discussed thoroughly
- The couple treats the DIY draft as a starting point, then has it reviewed by an attorney before signing rather than skipping legal review altogether
That last point matters most. Even couples who draft the substance themselves are generally better served having a lawyer review the final language before it’s signed, rather than eliminating legal involvement completely.
Why Independent Representation Matters So Much Here
Many states either require or strongly favor each spouse having their own separate attorney when a postnup is signed, and for good reason:
- A single attorney can’t ethically represent both spouses in a matter where their interests may diverge, even if the marriage is currently harmonious
- Separate counsel makes it far harder for either spouse to later claim they didn’t understand the agreement or were pressured into signing
- Courts often view postnups with separate representation as carrying significantly more weight than those without, simply because it demonstrates informed, voluntary consent
- The relatively modest cost of two attorneys reviewing a postnup is small compared to the risk of an agreement being thrown out entirely when it’s needed most
Frequently Asked Questions
Q1. Can a postnuptial agreement be thrown out even if both spouses signed it willingly?
Yes. Willing signatures alone don’t guarantee enforceability. Courts also examine whether full financial disclosure occurred and whether the terms were fair at the time of signing, meaning a voluntarily signed agreement can still fail if those other elements are missing.
Q2. Do both spouses need separate lawyers, or can one lawyer represent the couple together?
Most legal ethics rules prohibit one attorney from representing both spouses in a postnup, since their financial interests can genuinely conflict. Separate representation, even briefly for review purposes, significantly strengthens the agreement’s chances of holding up later.
Q3. How is a postnuptial agreement different from a prenuptial agreement in terms of legal scrutiny?
Postnups generally face somewhat closer scrutiny than prenups in many states, since the couple is already legally married and bound by certain mutual obligations at the time of signing, which can raise more questions about pressure or fairness than an agreement signed before the marriage began.
Q4. If we already have a written agreement between us, is it worth having a lawyer review it now rather than starting over?
Yes, this is often the most cost-effective path. Having an attorney review and refine an existing draft is typically far less expensive than full agreement drafting from scratch, while still addressing the enforceability gaps that commonly appear in self-drafted postnups.
