Anyone who can legally own property and understand what they are doing can set up a trust. In practice, that means any adult of sound mind, married couples acting together, business entities, and in some cases a legal representative acting on behalf of someone who cannot act for themselves. U.S. citizenship is not required. The core question is whether the person signing has the mental capacity the law demands and actually owns the property they want to place in the trust.
Adults of Sound Mind
An individual settlor — the person creating and funding a trust — generally needs to meet two conditions. You must be at least 18 years old, and you must be of sound mind at the moment you sign the trust document. These are the same baseline requirements the law uses for signing contracts and making other binding legal decisions.
“Sound mind” has a specific meaning here. At the time of signing, you need to understand what a trust is and what it does, what property you own and plan to put into it, and who your close family members and intended beneficiaries are. This is often called testamentary capacity, because it mirrors the mental ability required to make a valid will. Perfect memory and flawless judgment are not required. A basic grasp of your assets, your family, and the consequences of the document is.
Most states have adopted some version of the Uniform Trust Code. Section 601 of that model law sets the capacity needed to create, amend, or revoke a revocable trust at the same level required to make a will. The threshold is relatively low because a revocable trust can be changed or canceled at any time, so the law does not demand the same understanding it would for a permanent, irreversible decision.
Irrevocable Trusts Can Require More
The testamentary capacity standard applies to revocable trusts. Irrevocable trusts, which permanently transfer property out of your control, may require a higher level of capacity in many states. Because signing one is closer to making a final gift than drafting a changeable plan, courts in several jurisdictions apply contractual capacity, which asks whether you fully understand the nature and effect of the binding agreement you are entering.
The difference matters most at the margins. Someone with mild cognitive decline might have enough capacity to sign a revocable trust but not enough to irrevocably give property away.
Married Couples and Other Co-Settlors
Two or more people can create a single trust together as co-settlors. This is most common among married couples and domestic partners who want to manage shared wealth through one plan rather than keeping separate trusts. Both contribute their property, both typically keep the power to amend or revoke the trust during their lifetimes, and the document spells out what happens when one co-settlor dies.
Co-settlors should clearly establish the character of each asset going in. Property one spouse owned before the marriage may remain that spouse’s separate property inside the trust, while assets acquired together may be treated as joint property. Spelling this out in the trust document heads off disputes later.
Spousal Consent in Community Property States
If you live in Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, or Wisconsin, each spouse generally owns an equal share of property acquired during the marriage. You cannot give away your spouse’s half of a jointly owned asset, so transferring community property into a trust without your spouse’s consent can create serious problems. Both spouses should sign the trust document, or the non-settlor spouse should provide written consent, whenever community property is being transferred. Without that consent, the transfer can be challenged later.
Corporations, LLCs, and Other Business Entities
Business entities can create trusts just as individuals can. A company might set up a trust to manage employee benefits, hold commercial real estate, protect intellectual property, or achieve specific tax objectives. Because the entity is the settlor rather than any individual owner, the trust can survive changes in management or ownership.
A business entity acts through its authorized officers or managers, and its governing documents must permit the transaction. Corporate bylaws, an LLC operating agreement, or a partnership agreement should authorize the trust creation. Corporations typically pass a board resolution approving the trust and naming which officers may sign. Without that internal authorization, the trust can be challenged as beyond the officer’s authority.
Employer-sponsored benefit plans add a federal layer. When an employer creates a trust to hold assets for a pension, 401(k), or similar plan, the Employee Retirement Income Security Act requires the plan to be established under a written instrument that names one or more fiduciaries responsible for managing and administering it.1Office of the Law Revision Counsel. 29 U.S. Code 1102 – Establishment of Plan Those fiduciaries must act solely in the interest of participants and beneficiaries, with the care and diligence of a prudent person familiar with such matters.
Someone Acting on Another Person’s Behalf
Sometimes a trust needs to be created for a person who cannot act for themselves. Two paths exist, and each has its own limits.
Agents Under a Power of Attorney
A durable power of attorney lets a designated agent handle financial matters if you become incapacitated, but the authority to create a trust is not automatically included. Courts across multiple jurisdictions have held that an agent may create a trust only if the power of attorney document expressly grants that specific authority. A broadly worded clause giving the agent power over “all financial matters” is typically not enough. If you want your agent to be able to create, fund, or amend a trust on your behalf, the document needs to say so in plain terms.
Court-Appointed Guardians and Conservators
When someone has already lost capacity and no power of attorney is in place, a court can appoint a guardian or conservator to manage their affairs. A guardian can petition the court for permission to create a trust on the ward’s behalf, for example to shelter assets and preserve eligibility for government benefits, or to carry out an estate plan the ward would likely have wanted. The court holds a hearing, notifies interested parties such as family members, and decides whether the proposed trust serves the ward’s best interests. A guardian cannot create a trust unilaterally.
Non-U.S. Citizens
Citizenship is not required. Permanent residents, visa holders, and nonresident aliens can all establish trusts in the United States, as long as they meet the standard capacity requirements and own property they can transfer in. What changes with non-citizen settlors is the tax treatment.
A trust is treated as domestic — and taxed on its worldwide income — only if a U.S. court can exercise primary supervision over its administration, and one or more U.S. persons have authority to control all substantial decisions of the trust.2Office of the Law Revision Counsel. 26 USC 7701 – Definitions A trust that fails either test is classified as a foreign trust.
Creating or funding a foreign trust triggers reporting obligations. A U.S. person who creates one, or transfers money or property to one, must file IRS Form 3520. The penalty for failing to file is the greater of $10,000 or 35 percent of the gross value of the property transferred.3Internal Revenue Service. Instructions for Form 3520 (Rev. December 2025) Nonresident aliens whose trusts hold U.S. assets should also know that their federal estate tax exemption is substantially lower than the exemption available to U.S. citizens.
You Also Need Property to Put In
Mental capacity is only half of eligibility. You also need to own the property you intend to place in the trust. A trust with no property is an empty legal shell. The Uniform Trust Code requires that a valid trust have identifiable property, which means you must own the assets or hold a present legal interest in them when you create the trust. A promise to transfer something you hope to acquire later is not enough.
You can only transfer what you actually own. If you try to move an asset that belongs to someone else, or one you share with another person who has not consented, that portion of the transfer fails. Courts look for concrete evidence of ownership — recorded deeds, account statements, titles — when deciding whether a trust was properly funded. If you co-own property with someone who is not a co-settlor, you need their agreement before moving that asset into your trust.
When Someone Challenges Your Eligibility Later
Even after a trust is signed, someone can argue the settlor was not actually qualified to create it. These challenges, called trust contests, usually rest on one of two grounds: lack of capacity, meaning the settlor did not understand what they were signing, or undue influence, meaning someone manipulated the settlor into creating or changing the trust against their true wishes.
Not just anyone can bring a contest. The challenger generally needs a financial stake in the outcome — a named beneficiary, a beneficiary under a prior version of the trust, or someone who would inherit under state intestacy law if the trust were declared invalid. Strangers with no connection to the trust or the estate cannot file.
Courts evaluating capacity look at the settlor’s condition at the specific moment the trust was signed, not their general health before or after. A person with dementia may have had lucid intervals during which they could validly execute a trust. Evidence typically includes medical records, testimony from witnesses present at the signing, and proof of the settlor’s ability to describe their property and family at that time. If the court finds the settlor lacked capacity or was unduly influenced, it can void the trust or specific amendments to it.