The misconception that prenups are mainly about protecting the wealthy from a scheming spouse has given way to a more practical reality: prenups are financial planning tools that couples use to answer questions the law would otherwise answer for them. What they can cover is broad. What they cannot cover is narrower than most people assume, but the limits matter, because a prenup that strays into prohibited territory can undermine the validity of the entire agreement.
Property: what you own now and what you acquire during marriage
The core of almost every prenup is a set of agreements about property. Before the wedding, each partner typically has some combination of savings, real estate, investment accounts, retirement accounts, personal property, and perhaps business interests. A prenup can define all of these as separate property belonging to the partner who owns them, meaning they would not be divided at divorce. Without a prenup, state law determines whether premarital assets stay separate or become subject to division, and the rules vary significantly depending on whether you live in a community property state or an equitable distribution state.
Property acquired during the marriage is where the decisions get more nuanced. State law in most equitable distribution states treats income earned during the marriage as marital property subject to division at divorce. A prenup can modify this default. Couples sometimes agree that each partner's income remains their separate property throughout the marriage, or that only jointly titled assets will be treated as marital property. Others take the opposite approach and agree that everything acquired during the marriage will be shared equally regardless of who earned it, which sometimes produces a more protective outcome for a lower-earning spouse than state law would.
A few categories of property require careful drafting. Appreciation on separate property, that is, growth in value of an asset one partner owned before the marriage, can be treated as separate or marital depending on how the prenup addresses it and whether marital funds were used to maintain or improve the asset. Inheritance and gifts received during the marriage are treated as separate property under most states' default rules, but a prenup can confirm this or modify it. Business interests require particularly careful attention because a business can grow substantially during a marriage using the owner-spouse's labor and skill, and the question of how that growth is characterized is one of the most litigated issues in high-net-worth divorces.
Debt: protecting yourself from your partner's financial history
Prenups can address debt as directly as they address assets. If one partner is entering the marriage with significant student loans, credit card debt, or a business liability, the prenup can establish that this debt remains solely that partner's responsibility and that the other partner's assets cannot be reached to satisfy it. This matters most in states where marital property can be used to satisfy a spouse's debts, even debts incurred before the marriage.
Debt incurred during the marriage can also be addressed. Couples sometimes agree that debts taken on by one spouse without the other's consent, business debts, personal loans, or credit card balances, remain the sole responsibility of the spouse who incurred them. These provisions are most effective for protecting separate property; whether creditors are bound by a prenup's debt allocation is a separate question from whether the provision is enforceable between spouses.
Spousal support: what couples can agree to in advance
Prenups can modify or waive spousal support (alimony) rights that would otherwise apply under state law. This is one of the more consequential things a prenup can do, and courts evaluate alimony provisions more carefully than most other prenup terms because of the potential for hardship.
A complete alimony waiver is enforceable in most states when both parties were financially independent at signing, had independent counsel, and the marriage was not so long or the circumstances at divorce so unequal that enforcement would be unconscionable. A formula-based approach, tying support to years of marriage or a percentage of the income gap, tends to hold up better than a flat waiver because it acknowledges that circumstances change. Some couples include sunset clauses on alimony waivers: the waiver applies if the marriage ends within ten years, but after that the state's default rules govern. An attorney reviewing the agreement can advise on which approach is most defensible in the relevant state.
California courts scrutinize alimony waivers particularly closely and will not enforce a waiver that would leave a spouse without adequate means of support, regardless of what the prenup says. Texas courts have enforced alimony waivers but require that they be clearly voluntary. New York courts evaluate them under general contract principles. The enforceability of alimony provisions is one area where state-specific advice genuinely matters.
Business interests and professional practices
For entrepreneurs, business owners, and professionals with equity in a practice, the prenup's treatment of business interests is often the most financially significant provision in the agreement. Without a prenup, a business started before or during the marriage can become partially marital property, exposing it to division at divorce. A prenup can establish that the business is and remains separate property, that any increase in its value during the marriage stays separate, or that a formula determines how much of the growth is marital.
Business interest provisions work best when paired with a valuation of the business at the time of marriage. If the prenup states that the business is separate property but does not establish its current value, disputes arise at divorce about how much of the business's worth predates the marriage and how much grew during it. A formal valuation attached to the prenup, or at minimum a documented estimate with supporting records, gives the agreement a concrete baseline to work from.
Estate planning coordination: protecting children from prior relationships
Prenups are commonly used to protect the inheritance rights of children from a prior relationship. In states that give a surviving spouse certain automatic rights in a deceased spouse's estate, including the right to claim a share of assets regardless of what the will says (called an elective share or forced heirshare), a prenup can waive those rights. This allows each partner to leave their estate to their children without the new spouse having a legal claim to a portion of it.
This coordination between the prenup and estate planning documents requires care. The prenup's waiver of inheritance rights and the will's distribution scheme need to be consistent. A well-advised couple in a second marriage with children on each side typically executes the prenup and updates estate planning documents at the same time, making sure the two sets of documents work together rather than creating gaps or contradictions.
What a prenup cannot cover
Child custody and child support cannot be determined in a prenup. This is one of the clearest limits in family law. Courts decide custody based on the child's best interests at the time of divorce, a determination that requires looking at the actual circumstances of the child's life, not a contract signed before the child existed. Any prenup provision that attempts to predetermine custody arrangements, limit visitation, or waive child support will be ignored by the court entirely. It will not void the rest of the prenup, but it will carry no legal weight.
Provisions that try to regulate personal behavior during the marriage are generally unenforceable and can raise questions about the voluntariness of the whole agreement. A clause requiring one spouse to maintain a certain weight, specifying how often the couple must have sex, mandating a particular religion for children, or imposing financial penalties for infidelity crosses into lifestyle territory that courts do not treat as enforceable contract terms. Some of these provisions, particularly fidelity clauses, exist in a gray area: a few states have enforced them in limited circumstances, but they are unreliable enough that most family law attorneys advise against including them.
Anything that incentivizes divorce rather than addressing its financial consequences is unenforceable on public policy grounds. A provision paying one spouse a large bonus if the other files for divorce, or structuring financial benefits to trigger on the dissolution of the marriage, runs into this prohibition.
Provisions based on fraudulent financial disclosure void the agreement. If one partner deliberately concealed assets, misrepresented their financial picture, or provided materially false information at signing, the prenup is voidable by the deceived party. This is not a content limitation on what prenups can say; it is a process requirement that applies to all of them.
How a structured platform makes covering the right ground easier
One practical challenge in drafting a prenup is making sure the agreement actually addresses what the couple needs it to address. Many prenups focus narrowly on pre-existing assets and omit provisions about debt, business growth, or estate coordination that would have been worth including. A platform like HelloPrenup guides couples through the full range of topics that a prenup can address, surfacing decisions about property characterization, debt allocation, spousal support, and business interests as part of a structured process. Both partners answer the same questions together, which means nothing gets overlooked because one person was uncomfortable raising it.
A Real Scenario
A physician in Texas is getting married for the second time. She owns a medical practice valued at approximately $800,000 and has two teenage children from her first marriage. Her prenup establishes that the practice is her separate property, that any growth in its value during the marriage attributable to her labor is also separate, and that her new husband waives any elective share claim against her estate. Her will leaves the practice and the majority of her estate to her children. Without both documents, her husband would have had a statutory right to claim a portion of her estate at death regardless of her will's instructions. The prenup and updated estate plan working together achieve what neither could accomplish alone.
Frequently Asked Questions
Can a prenup protect my retirement accounts?
Yes. Retirement accounts accumulated before marriage are generally separate property under state law, but a prenup can confirm this explicitly and address how contributions made during the marriage will be treated. Without a prenup, the portion of a retirement account that grew during the marriage may be treated as marital property subject to division, even if the account predates the wedding. A prenup can define the entire account as separate, or establish a formula for separating the premarital and marital portions.
Can we include a clause about what happens if one of us cheats?
Fidelity clauses, provisions that impose a financial penalty for infidelity, are included in some prenups but their enforceability is unreliable. A handful of states have enforced them in limited circumstances. Others treat them as unenforceable on public policy grounds or as evidence that the agreement was coercive. If a fidelity clause is important to you, an attorney can advise whether it has any realistic chance of being enforced in your state and how to structure it to avoid tainting the rest of the agreement.
Can a prenup override my state's community property laws?
Yes, in large part. Community property states, California, Texas, Arizona, Nevada, Washington, and a few others, treat most income and assets acquired during the marriage as jointly owned by default. A prenup can opt out of this default, designating income and assets as separate property instead. The reverse is also possible: couples in equitable distribution states sometimes use a prenup to adopt community property-like rules. The prenup cannot override certain statutory protections, but it can substantially modify how the default rules apply to the couple's specific financial situation.
Can a prenup include a provision about the family home if we buy it after we get married?
Yes, and this is worth addressing explicitly. If one partner provides the down payment from separate funds and both names go on the title, without a prenup provision the home may be treated as partly or entirely marital property. A prenup can establish that the down payment is a separate property contribution, that only the portion of equity attributable to joint payments during the marriage is marital, or that one partner's separate funds used to purchase the home retain their separate character. These provisions work best when they are specific about how the accounting will work rather than simply declaring the home to be separate property.