What to know:
- In most states you can sign a valid prenup with one lawyer, or none, but a single lawyer cannot represent both partners because your interests can diverge.
- Under ABA Model Rule 1.7, a lawyer generally cannot represent one client when doing so is directly adverse to another current client, which is why one attorney drafting for both of you is a conflict of interest.
- A few states raise the bar: California requires independent counsel for each party for a spousal-support waiver to be enforceable, and New Hampshire courts have strongly recommended independent counsel for both parties.
- Courts weigh whether each partner had a real chance to consult their own lawyer when deciding if a prenup was signed voluntarily, and the absence of counsel for one side is a common basis for a later challenge.
- First lets both partners build the agreement together online, with independent legal review available to each side, so no one is relying on advice meant for the other partner.
You and your partner are trying to be practical. One of you already has a lawyer, or knows one, and paying for a second attorney feels like doubling the cost of something you both already agree on. So the question comes up: can we do this with one lawyer? It is a common, reasonable question, and the short version is reassuring. In most states, yes, you can sign a valid prenup with one lawyer, or even none. The wrinkle is not about how many lawyers sit at the table. It is about who each lawyer works for.
That distinction matters more than most couples expect, and it is where a lot of well-meaning DIY prenups run into trouble later. Under the Uniform Premarital Agreement Act, which along with its successor has been adopted by 29 states plus the District of Columbia according to the Uniform Law Commission, a prenup's enforceability turns on whether it was signed voluntarily and with fair financial disclosure. The number of lawyers is not the test. The quality of the process is. Let's walk through what that means in practice.
Can you legally get a prenup with only one lawyer?
In most states, a prenup does not require any lawyer at all to be legally valid. The base version of the Uniform Premarital Agreement Act imposes no independent-counsel mandate. What it requires is that the agreement be in writing, signed by both parties, and entered into voluntarily. If those boxes are checked, a court in a UPAA state will generally treat the document as enforceable, whether one lawyer drafted it, both partners had their own, or neither did.
So the legal minimum is low. That is the good news for cost-conscious couples. The gap worth understanding is the space between "legal" and "wise." A prenup signed with one lawyer can be perfectly valid on the day you sign it and still be more vulnerable if one partner later challenges it. Courts look at whether both people understood what they were signing and had a fair chance to get their own advice. When one partner had a lawyer and the other did not, that imbalance becomes something a judge can weigh. The document is not automatically void, but the process behind it is easier to attack.
If you want the fuller picture of what makes an agreement hold up, our guide on what makes a prenup enforceable walks through the voluntariness and disclosure standards in more depth.
Why can't one lawyer represent both of you?
Here is the part that surprises people. A single lawyer can physically draft the document, but that lawyer represents only one of you. Not both. This is not First's opinion or a soft professional courtesy. It comes from the ethics rules that govern every practicing attorney.
Under ABA Model Rule 1.7, a lawyer generally may not represent a client if that representation is directly adverse to another current client, or if there is a significant risk that the representation will be materially limited by the lawyer's duties to another client. A prenup is, by its nature, a negotiation between two people whose financial interests can point in different directions. What protects one partner's separate property might limit the other's claim to marital assets. A lawyer cannot fully advocate for both sides of that negotiation at once. Trying to do so is a conflict of interest.
So when someone says "we'll use my lawyer for the prenup," what is happening is that one partner has representation and the other does not. The lawyer owes their duty to one client. The other partner is, in effect, unrepresented, even if they sat in the same meetings. That is the reasoning behind the rule, and it is also why courts pay attention to whether both partners had their own advice. Our post on why two separate attorneys strengthen a prenup covers this dynamic in more detail.
What does "independent counsel" mean?
Independent counsel means each partner has their own attorney whose only job is protecting that partner's interests, rather than the two of you sharing a single lawyer. It is a straightforward idea once you separate it from the headcount. One lawyer serving both partners is not independent counsel, no matter how fair-minded that lawyer tries to be, because the lawyer's duty runs to one client.
There is a second layer worth understanding. In most states, the law does not demand that each partner hire a lawyer. What it protects is the opportunity to do so. A partner can often choose to proceed without their own attorney, sometimes by signing a written waiver of that right. What courts want to see is that the choice was real: that the partner had time, information, and a genuine chance to consult someone if they wanted to, and was not rushed or pressured into skipping it. Having a lawyer and having the opportunity to get one are different things, and the second is often what enforceability hinges on.
Which states require independent counsel?
Most states follow the general rule: no mandatory counsel, though independent advice strengthens the agreement. A small number raise the bar for specific situations, and it is worth knowing where the exceptions live so you do not assume the general rule covers you.
California is the clearest example. Under California Family Code §1612(c), a provision waiving or limiting spousal support is not enforceable unless the party against whom it is enforced was represented by independent counsel at the time the agreement was signed. Read that carefully. This is not a blanket California rule that every prenup needs two lawyers. It is a targeted rule about one type of provision, the spousal-support waiver. If your California prenup touches spousal support, independent counsel for each party becomes a condition of enforcing that term.
New Hampshire sits in a softer position. New Hampshire courts have strongly recommended independent counsel for both parties, though this is judicial guidance rather than a flat statutory command. The practical takeaway is the same in both states: where a court has signaled that it wants to see independent advice, giving each partner their own lawyer removes a line of attack.
Because these rules vary and change, our state-by-state guide to how prenups differ across America is the place to check your specific state before you assume the general rule applies.
Does a prenup hold up if only one partner had a lawyer?
In most states, yes, a prenup can be valid even when only one partner had a lawyer. But "can be valid" is doing some work in that sentence. Under UPAA Section 6, an agreement is not enforceable if the challenging party proves it was signed involuntarily, or that it was unconscionable when executed and there was no fair financial disclosure or valid waiver of disclosure. Unconscionable here means terms so one-sided that a court may refuse to enforce them.
Notice that missing counsel is not, by itself, on that list. What missing counsel does is feed the voluntariness question. When a judge is deciding whether a partner signed freely, the absence of that partner's own lawyer is one of the factors that gets weighed. Did the unrepresented partner understand the terms? Were they rushed? Did they have a real chance to get advice? A lopsided process, where one partner had a lawyer and every advantage and the other had neither, is one of the more common bases for a later challenge. Our guide on whether your prenup is fair digs into how courts read that fairness picture.
Here is how the staffing choices compare at a glance.
| Path | Who is represented | Allowed in most states? | Effect on enforceability |
|---|---|---|---|
| One lawyer drafting for both | Only the lawyer's actual client, not both | The document can be drafted, but the lawyer represents one side | Weaker; the unrepresented partner can later argue an uneven process |
| Two independent lawyers | Each partner separately | Yes | Strongest; clearest evidence of voluntariness |
| No lawyers | Neither | Often yes if formalities are met | Valid in many states, but a challenge is easier if disclosure or voluntariness is disputed |
| One lawyer plus independent review for the other | Each partner has their own review | Yes | Strong; each side gets independent advice |
What if one partner can't afford a lawyer?
This is where the "just use one lawyer" instinct usually comes from. One partner is driving the prenup, often the higher earner, and a second full attorney retainer feels like a stretch on top of a wedding budget. There are practical ways through this that keep the process fair.
The first is worth stating plainly: you can pay for your partner's independent attorney. This is common and generally fine. The one thing to protect is the choice. Your partner, not you and not your lawyer, should select the attorney who advises them. Paying the fee is acceptable. Controlling who sits in that chair can undermine the "independent" part of independent counsel, because the point is that the advice belongs to your partner alone. If you are working through affordability, our post on what to do if your partner can't afford a prenup covers the options.
The second path is a middle option that a lot of couples do not know exists. You do not have to choose between one lawyer and two separate five-figure retainers. Independent legal review for each side lets both partners get advice meant for them, without the full cost of back and forth with attorneys on both sides. If you are weighing the trade-offs across DIY, one-lawyer, and two-lawyer paths, that comparison is a good next read.
Frequently Asked Questions
Can one lawyer write a prenup for both of us?
A lawyer can draft the document, but they represent only one of you, not both. A single attorney cannot ethically advise both partners because your interests can diverge. The other partner should have their own lawyer, or at least a real opportunity to consult one, before signing.
Is a prenup valid if only one person had a lawyer?
In most states, yes, a prenup can be valid even if only one partner had a lawyer. But courts weigh whether the other partner had a genuine chance to get independent counsel when deciding if the agreement was voluntary. Missing counsel for one side is a common basis for a later challenge.
What does "independent counsel" mean?
Independent counsel means each partner has their own attorney whose only job is protecting that partner's interests. It is different from sharing one lawyer. Some states require it for specific provisions; most give each partner the right and opportunity to obtain their own lawyer if they want one.
Do I have to have a lawyer to get a prenup?
In most states you are not legally required to hire an attorney to sign a valid prenup, and a party can often waive that right in writing. Independent counsel still strengthens enforceability, and a few states require it for certain terms, such as California for spousal-support waivers.
Can I pay for my partner's lawyer?
Yes, paying for your partner's independent attorney is common and generally fine. The key is that your partner, not you or your lawyer, chooses that attorney. Paying the fee is acceptable; controlling the selection can undermine the "independent" part of independent counsel.
Building it together, with advice for each side
If you are weighing whether one lawyer is enough, the middle path is often the one that fits. First lets both partners build the agreement together online, with independent legal review available to each side so no one is relying on advice meant for the other. No shared lawyer, no lopsided process, no five-figure retainers on both sides. You set the terms with full information and time to decide. When you and your partner are ready, you can start your prenup with First.
Methodology
The adoption figure in this post reflects the Uniform Law Commission's record for the Uniform Premarital Agreement Act and its successor, which have been adopted by 29 states plus the District of Columbia. No original First statistics are cited here; the legal standards described come from the ABA Model Rules, the Uniform Law Commission's model act, and cited state code.
Sources
- ABA Model Rules of Professional Conduct, Rule 1.7: grounds the rule that one lawyer cannot represent both partners in a prenup.
- Uniform Law Commission, Uniform Premarital Agreement Act: supports the enforceability standard under Section 6 and the 29-states-plus-D.C. adoption figure.
- California Family Code §1612: supports the independent-counsel requirement for spousal-support waivers in California.
- Cornell Legal Information Institute, premarital agreement: plain-language definitional reference for premarital agreements.
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.