A postnup is a prenup signed after the wedding. Legally, the two are equal in power. Here is when a postnup makes sense, what it can do, and how to get one.
A postnuptial agreement typically costs $2,500 to $10,000 or more when billed hourly. Prenups.com drafts postnups for a flat $4,500, with negotiated agreements at $6,500. No hourly billing.
A postnuptial agreement is a contract signed by two people who are already married. It defines what belongs to each spouse, what belongs to both, and what happens to those assets if the marriage ends.
There are only two contracts that can replace one-size-fits-all state marital laws with terms a couple chooses for themselves: a prenuptial agreement and a postnuptial agreement. A prenup is signed before the wedding. A postnup is signed after. From a legal standpoint, the two documents are equal in power and reach. The distinction that matters is not strength. It is timing.
Until a couple trades vows and signs their marriage license, the partner who earns less holds exactly the same bargaining chip as the partner who earns more: the right to say “I do” or “I don’t.” The moment the marriage becomes official, that leverage disappears.
That is the entire reason a prenup is the better choice when it is available. Drawing the financial lines before a wedding creates a natural, definitive fresh start while both partners still stand on equal footing.
Amid the countdown to a wedding, some couples cannot make it to the attorney’s office to sign and notarize an otherwise finished prenup. When that deadline passes, the document is edited as needed and becomes a postnup. Others sign well into a marriage. The timeframe usually does not affect whether the agreement is enforceable.
Sometimes a couple seeks a postnup to save a marriage. Consider a spouse who left a demanding career years earlier to raise children full time, then discovered their partner had an affair. That discovery exposes how economically vulnerable the stay-at-home spouse has become. A postnup can build a financial safety net — for example, a trigger clause stating that if the marriage ends due to future infidelity, the at-fault spouse pays a specified alimony and the other spouse keeps a larger share of the marital estate. The point is not punishment. It is restoring enough security for the relationship to move forward.
When one spouse becomes an entrepreneur well into a marriage, a postnup can protect both partners. Take a couple where one spouse funds the household and the early research while the other builds a company that later attracts investors and acquisition interest. Joint ownership of patents and shares gets legally messy fast. A postnup can guarantee the supporting spouse a defined share of any future payout, whether it arrives during the marriage or after, without tangling up the company’s ownership structure in the meantime.
Some couples arrive at a postnup after years of the same argument about money. The agreement is not about preparing for divorce; it is about ending the ambiguity that keeps the argument alive. A postnup can set the household’s financial operating rules in a binding document: how income flows, who pays what, what gets saved, when a large purchase needs a conversation first, and an annual review where you look at the numbers together and reset goals. For many couples it is the first time the money conversation produces a decision instead of a fight.
A couple can have a genuinely good relationship and still have one piece of their finances causing steady friction. Usually the culprit is a big asset, most often a house. The pattern is familiar: one person owns a home before marriage, the spouse moves in, the title never changes, the original owner keeps paying the mortgage, and the other spouse covers a comparable shared expense in exchange. What sounded fair at the start starts causing fights. A postnup can establish a clear financial blueprint for who pays what and who owns how much, rather than leaving the arrangement to memory and goodwill.
Plenty of postnups begin life as prenups that a couple simply could not finalize before the ceremony. The document gets signed a few weeks later, and it becomes a postnup with no loss of legal force.
Postnups are legal and enforceable in most states, but the rules are not uniform and they continue to evolve. A few states impose extra execution requirements, such as additional witnesses. Some apply stricter scrutiny to postnups than to prenups. And a small number limit or decline to enforce postnups at all. This is exactly the kind of detail where an outdated online article can steer you wrong. Before relying on a postnup, confirm current enforceability and availability in your state, which is something the consultation covers directly.
California is the clearest example: spouses owe each other fiduciary duties under Family Code § 721, and courts review agreements between spouses with those duties in mind.
“Many states review a postnup more closely than a prenup because married spouses owe each other fiduciary duties, so fairness and full disclosure are not stylistic choices in the drafting. They are the enforceability test,” says Aaron Thomas, Esq., founder of Prenups.com and author of The Prenup Prescription.
One more requirement that surprises couples: consideration. Marriage itself is the consideration that supports a prenup, but a postnup is signed when you are already married, so some states require the agreement to be supported by its own consideration, such as mutual promises within the agreement or a meaningful change in financial rights. It is a drafting point most online sources skip, and one more reason postnups reward careful preparation.
The first is a do-it-yourself agreement that misses a simple procedural step, most often proper notarization or, in states that require them, witness signatures.
It starts with a conversation about what each spouse owns, what you owe, what you have built together, and what you want to happen under different scenarios.
From there, a licensed family law attorney drafts the agreement.
Both spouses review it, revisions and negotiation follow until both parties are satisfied.
The document is signed and notarized to your state’s requirements.
Every tier is a flat fee covering the full process from initial consultation through final signing, with no hourly billing. Full pricing is laid out on the pricing page.
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The only meaningful difference is timing. A prenup is signed before the wedding and a postnup is signed after. Legally, the two documents carry equal power. A prenup is generally the better choice when it is available, because both partners hold equal bargaining leverage before the marriage becomes official.
In most states, yes. Enforceability rules vary and continue to change. Some states impose extra execution requirements, some scrutinize postnups more closely than prenups, and a small number limit or do not enforce them. The consultation confirms what applies in your state before any work begins.
At Prenups.com, a postnuptial agreement is a flat fee starting at $4,500 for a standard postnup, with higher tiers for negotiated agreements and for Platinum postnups (starting at $13,000) involving high net worth or complex marital estates. Every tier is a flat fee with no hourly billing. Full pricing is on the pricing page.
It can help. Couples rebuilding trust after a breach sometimes use a postnup to restore a sense of financial security, which makes it easier to move forward. Spelling out terms while both partners are still civil can also make an eventual separation far less contentious if it comes to that.
Practically speaking, yes. Do-it-yourself postnups routinely fail over simple procedural errors like improper notarization or missing witness signatures, and estate planning attorneys often miss the specifics that family law requires. A licensed family law attorney who works in divorce court knows what makes these agreements hold up.
Yes. A postnup can define how a business started during the marriage is owned and how any future sale or payout is divided, which protects both the founding spouse and the one who supported the household while the business was built.
