Prenup vs. Postnup Cost: What Each One Really Costs and Why Timing Changes the Price

You are weighing two agreements and one question sits at the front of your mind: which one costs less? It is a fair thing to ask, especially if you are engaged, or newly married, and trying to plan sensibly. The short version is that a prenup is usually the lower-cost path, and the reason has less to do with the paperwork than with when you sign it. Traditional attorney-drafted prenups typically run $3,000 to $10,000 or more per couple, while flat-fee online platforms start around $649 including notarization, according to the 2025 Clio Legal Trends Report and Bureau of Labor Statistics wage data. A postnup, the version you sign after the wedding, tends to land at the same price or a little higher.

Let's walk through what each one costs, why the timing moves the number, and how to think about value for your own situation.

Which one do you need, and what does it cost?

The choice between a prenup and a postnup comes down to one thing: whether you are married yet. A prenup is signed before the wedding. A postnup is the same idea, signed after you are already married. Both set out how you and your partner would handle property, debt, and support if the marriage ended. (For a fuller side-by-side, our guide on the difference between a prenup and a postnup covers the ground.)

On cost, here is the answer most people are looking for. A prenup drafted by attorneys usually runs $3,000 to $10,000 or more per couple, driven by the 2025 Clio Legal Trends Report figures on family-law billing. A flat-fee online prenup starts around $649. A postnup covering the same ground tends to cost the same or slightly more. The common assumption, that you can skip the prenup now and grab a cheaper postnup later, usually does not hold up, and the reason is worth understanding before you decide.

How much does a prenup cost?

If you have looked into attorney-drafted prenups, you have probably noticed the price ranges are all over the place. That is because most attorneys bill by the hour, and the hours add up quickly once two lawyers start trading drafts. The 2025 Clio Legal Trends Report puts the national family-law hourly rate at $312, the single biggest reason traditional prenups often run into the thousands. Add the fact that the median annual wage for lawyers was $151,160 in May 2024, according to BLS Occupational Employment and Wage Statistics, and it is clear why attorney time is the largest line item on the bill.

A straightforward prenup might take a handful of hours. A complex one, with a business, real estate, and back and forth negotiation between two attorneys, can take many more. That is how a $3,000 agreement becomes a $10,000 one. The complexity matters, but the billing model matters more. Our cornerstone guide on how much a prenup costs breaks the ranges down further.

The flat-fee online path works differently. Instead of an open-ended hourly meter, you pay a set price for the agreement. First's flat-fee online prenup starts around $649 and includes notarization, with an option for independent attorney review for each partner. No PDFs to wrangle, no hourly rates, no guessing at the final bill. If you want to compare the two paths head to head, our DIY prenup versus lawyer breakdown lays out where each one fits.

How much does a postnup cost?

Here is where the "cheaper later" idea tends to unravel. A postnup covering the same assets and terms as a prenup usually costs the same, and often slightly more.

Why? Two reasons, and both trace back to timing. First, a postnup often pushes both spouses toward separate attorneys, because courts want to see that each person had independent advice on an agreement signed inside a marriage. Second, the financial disclosure tends to be fuller, since courts scrutinize post-marriage agreements more closely. Separate lawyers plus more documentation means more hours, and more hours means a higher bill at the same $312 hourly rate the Clio report cites.

We are not going to quote a hard dollar range for postnups here, because the reliable, sourced figures we trust do not pin one down cleanly. What the family-law landscape does support is the direction: a postnup is rarely the bargain it looks like from the outside. If a postnup is the right call for your situation, and sometimes it is, you will want to consult independent legal counsel about a postnuptial agreement. Postnups sit outside what First offers, so a family-law attorney in your state is the right person to price and draft one.

Why does timing change the price?

This is the part that surprises people, so it is worth slowing down.

Before you are married, you and your partner are, in the eyes of the law, two independent people who can each still walk away. Courts treat that as arm's-length bargaining, meaning neither side has a built-in advantage and each can say no. That assumption keeps the review of a prenup relatively standard.

After the wedding, the picture shifts. Married spouses owe each other fiduciary duties, a legal obligation to act in good faith and deal fairly with one another. You can no longer walk away as freely, and your finances are now intertwined. Because of that, courts apply heightened scrutiny to postnuptial agreements, looking harder at whether the deal was fair and whether both people disclosed everything. That closer look is what nudges couples toward separate attorneys and fuller paperwork, and that is what adds cost.

There is also a quieter legal issue called consideration, the thing of value each party gives up when they sign a contract. For a prenup, the mutual promise to marry usually counts as that value. For a postnup, you are already married, so the "what is each side giving up" question gets trickier, and some states handle it differently. It is one more reason postnups can be harder to support and, in practice, more expensive to draft carefully.

State rules add another layer. The Uniform Premarital Agreement Act and its successor, the Uniform Premarital and Marital Agreements Act, have been adopted by 29 states plus the District of Columbia, according to the Uniform Law Commission. That means the rules governing these agreements, and how postnups are treated in particular, are not uniform across the country. A few states barely recognize postnups at all. Costs and enforceability both vary by where you live.

Prenup vs. postnup: which is the better value for your situation?

For most couples who are not yet married, a prenup is the lower-cost, cleaner option. You get the standard review, the arm's-length assumption works in your favor, and you have the flat-fee online path available. A postnup makes sense when circumstances change after the wedding, an inheritance arrives, a business takes off, one partner takes on significant debt, but it is generally not the way to save money.

Here is the head-to-head.

If you are still comparing the flat-fee route against hiring an attorney by the hour, our online prenup buyer's guide walks through what to look for, and finding a prenup lawyer near you covers what hourly attorney work involves if that is the path you prefer. For broader context on how common these agreements have become, see our roundup of prenup statistics.

Frequently asked questions

Is a postnup more expensive than a prenup?

Usually about the same, sometimes slightly more. A postnup often pushes both spouses toward separate attorneys and fuller financial disclosure, because courts scrutinize agreements signed after marriage more closely. Those two factors add hours and fees, so the equivalent postnup can cost a bit more than the prenup would have.

How much does a prenup cost?

Traditional attorney-drafted prenups typically run $3,000 to $10,000 or more per couple, while flat-fee online platforms start around $649 including notarization, according to the 2025 Clio Legal Trends Report and Bureau of Labor Statistics wage data. The billing model matters more than your location.

Why does timing change the price of these agreements?

Before marriage, each partner can still walk away, so courts assume a level bargaining field. After marriage, spouses owe each other fiduciary duties, so courts look harder at fairness and disclosure. That heightened scrutiny nudges couples toward separate lawyers and more documentation, which adds cost.

Is a postnup as enforceable as a prenup?

It can be, but it generally faces more scrutiny. Courts apply heightened review to postnups because already-married spouses cannot bargain at arm's length, and a few states barely recognize them. A well-drafted postnup with independent counsel and full disclosure can hold up, but the bar is higher.

Can I do a cheaper postnup later instead of a prenup now?

It rarely saves money. A postnup often costs the same or more, and it faces tougher court scrutiny. If you are not yet married, a prenup is usually the cleaner, lower-cost path. Postnups exist for good reasons, but "cheaper" is generally not one of them.

Getting started with First

If you are not yet married, a prenup is usually the lower-cost, cleaner path, and First makes it a flat-fee online process with an option for independent attorney review for each partner. No hourly rates, no guessing at the final bill, no surprises. If you would like to see what fits your situation, you can start by answering a few questions to explore your options.

Costs and enforceability rules vary by state, and the price ranges here are national estimates as of 2026. If a postnup turns out to be the right fit for your circumstances, consult independent legal counsel about a postnuptial agreement, since that work sits outside what First offers.

Methodology

These figures are drawn from the 2025 Clio Legal Trends Report, which analyzes aggregated, anonymized billing data from tens of thousands of U.S. legal professionals, and the Bureau of Labor Statistics Occupational Employment and Wage Statistics survey (May 2024 release). First's flat-fee pricing is first-party. Price ranges are national estimates as of 2026; actual costs vary by state, attorney, and case complexity.

Sources

First is not a law firm. The information and tools provided by First on this site are not legal advice and not a substitute for the advice of an attorney.