South Dakota Premarital Agreements

POV: You're about to walk down the aisle with your beloved in the picturesque landscapes of South Dakota, and you feel secure in your financial future because you’ve signed an ironclad premarital agreement. What could be better than that? Not much, if you ask us! Let’s talk about premarital agreements, sometimes called a prenuptial agreement, antenuptial agreement, or the most commonly used term, “prenup.” In South Dakota, the “prenup” is referred to as a “premarital agreement.” Now, in the land of South Dakota, guidelines for premarital agreements are outlined under the South Dakota Codified Laws, Title 25, Chapter 25-2. Once you are married, your prenup will take effect. So, whether you label it a premarital agreement, prenup, antenup, or pre-love arrangement, just remember that it's all about ensuring that your love story continues to shine against the captivating South Dakota backdrop!

Who should consider getting a premarital agreement?

Whether you live in South Dakota or the Big Apple, a premarital agreement is a good idea. We know we might be biased because, hello, we love prenups, but keep reading to hear some unbiased information on who should consider getting a premarital agreement in South Dakota:

People who own assets prior to getting married

If you have a checking account, real estate, or even if you own something obscure like horses, those are considered assets! If you enter a marriage with assets, you may want to consider protecting them with a prenup. The default state law in South Dakota doesn’t always protect you. However, a prenup can safeguard those assets even if the law doesn’t.

People with children from previous relationships

If you had kids prior to meeting your new partner, and you want your money to stay in the family and go to your children, then a premarital agreement may help you achieve that goal. Think about it this way: if you have a prenup that safeguards your assets from your spouse in the event of a divorce, you are effectively saving that money for your children’s future.

People with high future earning potential

Maybe you don’t have anything now, but you will in the future. Maybe you’re in med school or grad school, and you know you will be making the big bucks one day. A premarital agreement can ensure your future income and assets purchased with future income are protected in the event of divorce.

People who have businesses or plan to start businesses (family farms included)

If you have an entrepreneurial spirit, listen up. Prenups can protect businesses, including family farms. If you are located in South Dakota, maybe your business is a family farm or some other type of food company, and you want to protect it. That would be totally reasonable and doable with a premarital agreement. Without one, you could stand to lose a portion of the value of your business in a divorce.

People who want clarity and peace of mind

If for nothing else, a premarital agreement can provide clarity to a married couple and financial peace of mind. A premarital agreement is like a predetermined guide for how you want your money to be divided in a divorce (and sometimes in death). This can help you and your partner rest assured that both of your goals are met with this contract, even if the partnership comes to an end.

The UPAA/UPMAA

What the heck is a “UPAA/UPMAA?” It’s a fancy legal acronym for the “Uniform Premarital Agreement Act” and the “Uniform Premarital and Marital Agreements Act.” The UPAA and UPMAA essentially set out to unify all prenup laws across the United States. It sets guidelines for states to adopt regarding prenup laws. For example, one guideline laid out by the UPAA is putting the premarital agreement in writing and requiring both spouses to sign it. Pretty straightforward, right? Right! There are many other “rules” that these Acts lay out, and it’s up to the states as to whether they want to adopt them 100% or partially. As of 2025, twenty-nine states, including the District of Columbia, have adopted the UPAA. Two states have adopted the UPMAA (it’s a stricter version of the UPAA). South Dakota is one of the twenty-nine states that have adopted the UPAA.

What makes a South Dakota premarital agreement enforceable?

First, let’s talk about what it means to be “enforceable.” If a prenup is “enforced,” it means that a court has essentially told a divorcing couple that they need to follow the terms of their own prenup agreement. There are certain factors that make a prenup enforceable, which are laid out by each state’s legislature. What is an enforceable prenup in South Dakota may not be enforceable in New York. So, what does South Dakota require for a premarital agreement to be enforceable? Let’s start with the general formalities:

• Put the agreement in writing
• Make sure both partners sign it
• Both partners must sign the agreement voluntarily (i.e., not under some type of force like duress) in order for it to be enforced.
• A premarital agreement cannot be enforced if it is very unfair (i.e., unconscionable) when it was signed, and one person didn't know the other person's finances or wasn't given enough information about them, the agreement may not be legally valid.
• The agreement includes clauses against South Dakota’s laws or public policy

At the end of the day, these enforceability requirements are pretty simple when you think about the big picture: put it in writing, sign it, don’t force your partner to sign it, don’t include illegal clauses, make sure it’s reasonable, and disclose your finances.

What can you put in a South Dakota premarital agreement?

So, what actually goes into a premarital agreement? Well, each state dictates what can (and cannot) go into a premarital agreement. In South Dakota, there are several topics you can cover in your premarital agreement:

• The division of property in the event of a divorce
• The division of certain property in the event of death
• Life insurance arrangements
• Any other matter not against South Dakota policy or law

Maybe more important to understand is what you cannot include in a South Dakota premarital agreement:

• Limitations or elimination of child support
• Instructions on child custody
• Limitations or elimination of spousal support

In other words, you cannot write into your prenup anything about child support and/or spousal support. South Dakota law says child support and spousal support matters are up to the state, and not for private individuals to contract over. See more about what you can and cannot include in your South Dakota premarital agreement in Section 25-2-18 of the S.D. Codified Laws.

Important case law regarding premarital agreements in South Dakota

Case law helps us understand how the South Dakota judiciary treats prenuptial agreements. Let's take a look at how courts analyze and enforce prenups:

No waivers of spousal support in South Dakota premarital agreements

In this case, there was a couple who signed a premarital agreement before getting married. Basically, they said they wouldn't ask for money from each other if they ever got divorced (i.e., spousal support). Later on, they did get divorced, and one of them wanted spousal support. The result? The court said that this agreement wasn't fair because it's hard to predict the future and it’s in the public’s interest for a husband to support his wife (remember, this was the late 70’s). So, they decided that the agreement couldn't be enforced, and they sent the case back to the lower court for more discussion. While this is an older case, this is still the law of the land in South Dakota– you cannot waive or alter spousal support in your South Dakota prenup. (Connolly v. Connolly)

A continuation of the spousal support in premarital agreements issue in South Dakota

In this case, Edward and Debra divorced after an eleven-year marriage. Before marrying, they signed a premarital agreement, waiving rights to each other's property, alimony, and attorney's fees in case of divorce (i.e., neither person got the other’s property, neither person had to pay alimony, and neither person had to pay the other’s attorney fees). In the divorce proceedings, Edward requested alimony even though his prenup explicitly said it wasn’t allowed. Either way, the court said no because they found he did not demonstrate a need for it. But the court also said it didn’t matter what the prenup said about alimony because alimony provisions in prenups are still unenforceable! However, regarding attorney’s fees, the court declared that a waiver of attorney's fees may not be applicable in a prenup as it pertains to spousal support. In other words, you might get your waiver of attorney’s fees clause thrown out by a South Dakota judge and actually be required to pay attorney’s fees. (Walker v. Walker)

The bottom line on South Dakota premarital agreements

From the UPAA to the legal requirements to the benefits of a prenuptial agreement in South Dakota, you now know everything you need to know about getting a prenup in your beautiful state. Remember to follow the laws laid out by the South Dakota legislature and case law to ensure your agreement stands the test of time and holds up in court one day if it is ever challenged. Things like proper financial disclosure and entering into the agreement voluntarily are incredibly important to a South Dakota prenuptial agreement. So go on and get that prenup started. Your future self will thank you. Happy prenup planning!