Yes — if you have one child, you need a will, and arguably more urgently than parents with several. Dying without one hands the decisions to your state’s intestacy rules, and those rules rarely match what a one-child parent assumes will happen. The common belief that “my only child gets everything” is wrong in most states whenever a surviving spouse is in the picture, and if your child is a minor, the court also picks who raises them and who controls the money. A will is how you keep those choices.
What Your State Does If You Skip the Will
Intestacy laws are the default distribution rules that kick in when there’s no will. Under the pattern followed by many states, a surviving spouse takes a lump sum off the top, somewhere in the range of $150,000 to $300,000 depending on the family situation, plus a fraction of the remainder. The child gets what’s left. The exact split turns on whether the child is also the surviving spouse’s child and whether the spouse has other descendants. Very little of this looks like “everything to my kid.”
If you’re unmarried or widowed, intestacy still creates work. The probate court has to formally identify your heirs, which costs time and legal fees. If your child is under 18, the court appoints someone to manage the inheritance, and that person may not be who you would have chosen.
Naming a Guardian for Your Child
If your child is a minor, the guardian nomination is the single most important reason to have a will. Without one, a judge decides who raises your child, working from the best-interests standard but without your input. The judge might pick a relative you would have chosen. They might not.
A guardian named in a will is called a testamentary guardian, and courts in most states honor that nomination unless someone objects and shows the person is unfit. Name a backup as well. The person you trust today might be dealing with illness, a move, or their own family pressures when the time comes, and a single name leaves the same gap you’re trying to close.
One boundary to be clear about: if your child’s other parent is alive, that parent generally has priority for custody no matter what your will says. The guardian nomination matters most when both parents are gone or the other parent is absent or unfit. Even then, putting your choice in writing strengthens the surviving parent’s position if a relative pushes for custody.
Who Controls the Money Until Your Child Is Grown
Minors can’t legally own or manage inherited assets. If you leave property to a child under 18 without a management structure, the court builds one for you. That typically means a conservatorship: a court-appointed manager, a surety bond equal to the estate’s value, periodic reports to the court, and a hard cutoff where everything transfers to the child the day they turn 18.
A will lets you replace that with a testamentary trust — a trust created by the will itself, run by a trustee you choose, on terms you set. You might allow distributions for education and health during childhood and hold the balance until 25 or 30 rather than release it at 18. The trustee follows your instructions, not a judge’s schedule.
For smaller inheritances, a custodial account under the Uniform Transfers to Minors Act is simpler but blunter. The custodian manages the assets until the child hits the age your state designates, usually 18 or 21, and then the child takes full control with no conditions. If you want any hold past that age or any strings on distributions, a testamentary trust is the better tool.
The Assets Your Will Doesn’t Control
This is where one-child families most often trip up. Several major categories of property pass outside your will entirely, going straight to whoever is on the beneficiary form. If your will leaves everything to your child but an old form still names an ex-spouse, the ex-spouse collects. Courts consistently enforce the designation over the will.
- Retirement accounts — 401(k)s, IRAs, and pensions go to the beneficiary on file with the plan administrator.
- Life insurance — proceeds go to the policy’s listed beneficiary; naming your estate is almost always a mistake for tax and probate reasons.
- Payable-on-death bank accounts — the person on the POD form collects directly from the bank.
- Jointly held property — real estate or accounts held in joint tenancy with right of survivorship pass automatically to the surviving co-owner.
- Transfer-on-death securities and, in roughly 30 states, TOD real estate — pass directly to the named beneficiary.
Review every beneficiary designation at least once a year, and always after a divorce, marriage, or death in the family. Your will and your beneficiary forms should tell the same story. When they contradict each other, the forms win.
Making the Will Legally Valid
A will that doesn’t meet your state’s formal requirements is worth nothing, so this is not the corner to cut. Specifics vary, but the baseline in most states looks the same: you must be at least 18, mentally competent (meaning you understand what you own, who your family is, and what the will does), the document must be in writing, you must sign it, and at least two witnesses who aren’t beneficiaries must sign as well. Some states also require notarization.
Add a self-proving affidavit. It’s a sworn statement, signed by you and your witnesses in front of a notary, confirming that the will was properly executed. Nearly every state recognizes them, and the payoff is real: without one, your witnesses may have to appear in court after your death to authenticate the will. With one, the court accepts the document without hunting anyone down.
Choosing Your Executor
Your executor handles the practical wind-down: filing the will with the probate court, inventorying assets, paying debts and taxes, and distributing what remains to your child.1Internal Revenue Service. Responsibilities of an Estate Administrator With a single beneficiary the job is more straightforward than in multi-heir estates, but it still involves court filings, creditor notices, and tax returns.
Many parents with one child name that child as executor, which works well once the child is an adult. If your child is a minor, pick someone else — organized, financially literate, and willing to serve — and name an alternate. If your first choice lives out of state, know that some states impose extra requirements on out-of-state executors, such as posting a bond, appointing a local agent for legal documents, or serving alongside an in-state co-executor.
Your will can waive the bond requirement, which saves the estate the cost of a surety bond. This is common when the executor is a trusted family member or the sole beneficiary, since the bond mainly exists to protect beneficiaries from executor misconduct.
Planning for What Could Go Wrong
A will that names only your child as beneficiary and stops there has a real blind spot. What if your child dies before you? Without a backup plan, the assets fall into intestacy and go to relatives you may never have chosen.
The fix is a contingent beneficiary clause. Name your child as primary, then specify who inherits if the child can’t. If your child has children of their own, adding “per stirpes” language sends your child’s share down to their descendants rather than redirecting it. Without that phrase, the grandchildren can be shut out entirely.
If your child has creditor problems, a pending divorce, or a habit of spending everything at hand, a spendthrift provision inside a testamentary trust can shield the inheritance. Spendthrift language prevents the beneficiary from pledging or assigning trust assets before distribution and blocks creditors from reaching the money while it sits in the trust. The trustee controls the pace of distributions on the terms you set.
Keeping the Estate Out of Probate Where You Can
Probate is the court-supervised process of validating the will and distributing the estate. It works, but it’s slow (often 6 to 18 months), public, and comes with filing fees and attorney costs. A one-child family has good options for moving assets around it.
Transfer-on-death deeds, authorized in roughly 30 states, let you pass real estate directly to your child without probate. You record the deed during your lifetime, but it has no effect until your death, so you keep full ownership and can revoke or change the beneficiary anytime. For financial accounts, POD and TOD designations do the same thing. Between TOD deeds and beneficiary designations, a single-child family can often move most assets outside probate with modest paperwork.
If probate is unavoidable, many states offer a simplified small-estate procedure when the total value falls below a threshold. Thresholds vary widely by state. Qualifying can turn a months-long process into a matter of weeks.
One caution: TOD deeds and beneficiary designations that name a minor recreate the management problem. The child can’t legally take control of the asset, so a court-appointed conservator or custodian ends up involved anyway. If your child is under 18, a trust is generally the cleaner solution.
Protecting Against a Will Challenge
Contests are less common when there’s a single child and no competing beneficiaries, but they still happen. The most frequent are a disinherited spouse claiming an elective share, a family member alleging undue influence, and someone arguing the will wasn’t properly executed.
A surviving spouse has a right in most states to claim an elective share, typically around one-third, even if the will leaves everything to your child. The right exists to prevent a spouse from being cut out entirely. It can be waived through a prenuptial or postnuptial agreement, but without a waiver the spouse can override the will.
To reduce undue-influence risk, work with your own attorney rather than one recommended by the beneficiary, and keep beneficiaries out of the drafting process. If there’s any question about your mental capacity, a medical evaluation at the time of signing creates strong evidence that you knew what you were doing.
A no-contest clause (sometimes called an “in terrorem” clause) provides that anyone who challenges the will forfeits their inheritance. Most states enforce them, though several add a “probable cause” exception for challengers with legitimate grounds, and a handful, including Florida, refuse to enforce them at all. If your estate is straightforward and your child is the sole beneficiary, the clause may be unnecessary, but it costs nothing to include.
Don’t Forget Digital Assets
Online accounts, digital businesses, cryptocurrency wallets, and social media profiles are part of your estate, and they’re easy to overlook. Most platforms’ terms of service prohibit anyone else from accessing your account after you die. Nearly every state has adopted the Revised Uniform Fiduciary Access to Digital Assets Act, which lets you override those terms by explicitly granting your executor authority over digital assets in your will.
“Explicitly” is the word that matters. If your will is silent, the platform’s default controls, and most defaults lock your executor out. Include language authorizing your executor to access, manage, and distribute digital assets, and separately keep an inventory of accounts, passwords, and two-factor methods somewhere your executor can reach. A password manager with emergency access features handles this well, and a written list stored with your estate documents also works.
Some platforms offer their own legacy-contact or inactive-account tools. Where you’ve used one, the platform’s setting generally overrides both your will and the default terms, so make sure whoever you designated there matches your broader plan.