A last will and testament does not expire. Once it has been signed, witnessed, and executed under the laws in force at the time, it stays legally valid until the person who made it revokes it or replaces it. A will signed thirty years ago carries the same legal weight as one signed last week. What can change, and often does, is whether the will still does what its author wanted, because divorce, marriage, new children, a move to another state, and shifts in tax law can undo specific provisions or produce results the testator never had in mind.
So the honest answer to how long a will lasts has two parts. Legally: indefinitely. Practically: only as long as the life it was written for still looks like the life the testator has.
A Will Has to Have Been Valid to Begin With
Age doesn’t fix a defective will, and age doesn’t break a properly executed one. Every state sets its own execution rules, but the core requirements overlap. The testator must be of legal age (18 in most states) and of sound mind at the moment of signing, meaning they understand they are creating a will, have a general sense of what they own, and recognize the people who would naturally inherit from them. A dementia or mental illness diagnosis doesn’t automatically disqualify someone; clarity at the signing is what matters.
The will must be in writing, signed by the testator (or by someone signing at the testator’s direction and in their presence), and signed by two disinterested adult witnesses. “Disinterested” means the witnesses are not named as beneficiaries. In most states, a beneficiary who acts as a witness doesn’t invalidate the whole will, but under state “purging” statutes that witness may lose their inheritance. The safe practice is to use witnesses with no stake in the document.
Some formats sit outside the standard witnessed will. Roughly half the states recognize holographic wills, which are handwritten and signed by the testator but not witnessed. A smaller and growing group of states recognize electronic wills, which must be readable as text and signed electronically, and which typically still require witnesses to be physically present. A holographic or electronic will that was valid where it was made doesn’t lose validity with time, but proving one up in probate decades later — or after the testator has moved to a state that doesn’t recognize the format — can be harder than proving up a standard witnessed will.
What Can Revoke a Will
A will stays valid until something specific ends it. Three things do most of the work.
Signing a new will. The most common way to revoke a will is to execute a new one. A well-drafted new will opens with a clear revocation clause (“I revoke all prior wills”). Without that language, courts have to decide whether the new document was meant to replace the old one or supplement it, and that ambiguity is a common source of litigation.
Physical destruction. Tearing, burning, or shredding a will revokes it, but only when the testator does so intending to revoke. A will destroyed accidentally in a house fire is not revoked. Intent and act have to go together. If a will known to have been in the testator’s possession cannot be found after death, most states presume the testator destroyed it on purpose. That presumption can be rebutted, but doing so requires strong evidence.
Divorce. In the vast majority of states, a divorce or annulment automatically voids the provisions in the will that benefit the former spouse — gifts, executor appointments, powers granted to the ex-spouse. The rest of the will stays in force. Marriage does not have the same effect, which is where a lot of old wills quietly stop reflecting the testator’s real wishes.
Life Changes That Leave the Will Valid but Off-Target
These are the situations where the will is still legally good and still wrong for the reader’s life.
Marrying After the Will Was Signed
If someone marries after making a will and the will doesn’t mention the new spouse, most states treat that spouse as an “omitted spouse.” The surviving spouse generally has a right to claim a share of the estate, often the share they would have received had the testator died without a will at all. That can redirect a large portion of the estate away from the people originally named. The protection typically doesn’t apply if the will was clearly made in contemplation of the marriage or if the testator provided for the spouse in another way, such as a trust or life insurance.
A Child Born or Adopted After the Will Was Signed
A child born or adopted after the will is signed, and not mentioned in it, may qualify as a “pretermitted heir.” Most states give pretermitted children a share of the estate even though the will is silent about them. The size of the share depends on whether the testator had other children when the will was signed and what those children received. The protection doesn’t apply where the omission was clearly intentional or the testator provided for the child outside the will.
Both rules exist because the law assumes leaving out a new family member was an oversight. The cleanest fix is to update the will after any major family change.
Moving to Another State
A will properly executed in one state is generally accepted as valid in another. The Full Faith and Credit Clause supports that principle, and most states have statutes explicitly recognizing wills executed under another state’s laws. A move across state lines doesn’t invalidate a will on its own.
A move can still cause trouble. State laws differ on witness rules, community property, and surviving-spouse protections. A will drafted in a common-law property state may not account for community property rules if the testator moves to one of the nine community property states. Provisions that were fine in the old state may be unenforceable in the new one. A will review with a local attorney after a cross-state move is worth the modest cost.
Practical Problems With Old Wills
Even a valid will can be hard to use if the paperwork around it has aged badly.
Missing witnesses. Without a self-proving affidavit, the probate court typically needs at least one of the original witnesses to confirm the will is authentic. If the witnesses have died, moved, or can’t be located, proving up the will gets harder. A self-proving affidavit is a notarized statement, attached to the will at signing, in which the testator and witnesses swear the will was properly executed. It doesn’t change validity; it changes provability. Adding one at signing time usually costs no more than a notary fee and can save significant trouble decades later.
A lost original. When the testator kept the original and it can’t be found after death, most states presume it was intentionally destroyed. That presumption is rebuttable, but doing so requires strong evidence: a photocopy or draft, testimony from the drafting attorney, or witnesses to the testator’s continuing intentions. Probating a copy is possible and harder than probating an original. Storing the original in a fireproof safe, with the drafting attorney, or on file with the local probate court where allowed avoids the problem.
Challenging an Old Will After Death
An old will that meets every formal requirement can still be overturned if someone proves it was the product of coercion or fraud. Most contested probate cases sit here, and the window opens only after the testator can no longer explain their intentions.
Courts will invalidate a will procured by undue influence: not persuasion or suggestion, but pressure that overcame the testator’s free will. They weigh the testator’s vulnerability (age, illness, isolation, cognitive decline), the influencer’s position of power (caretaker, attorney, family member controlling finances), and whether the result looks like something the testator would have chosen on their own. A common pattern involves a caretaker isolating an elderly testator from family and ending up as the primary beneficiary. Some states apply a presumption of undue influence when a person in a confidential or fiduciary relationship with the testator both helped create the will and benefits from it, shifting the burden to that person to prove the will reflects the testator’s genuine wishes.
Some wills include a no-contest clause (also called an “in terrorem” clause) providing that any beneficiary who challenges the will forfeits their inheritance. These clauses are enforceable in most states, though many will not enforce them where the challenger had probable cause for the contest. The practical effect is real: a beneficiary with a moderate inheritance thinks twice before risking it all.
When to Review a Will
A common rule of thumb is to review a will at least every five years even if nothing obvious has changed. Certain events should prompt an immediate review:
- Marriage, divorce, or remarriage.
- Birth or adoption of a child.
- Death or incapacity of a beneficiary or executor.
- A significant change in assets, such as a home purchase, inheritance, or business interest.
- A move to a new state.
- Changes in federal or state tax law, particularly for wills that contain formula clauses tied to the estate tax exemption.
The last point is worth pausing on because it affects a lot of older wills right now. The federal estate tax exemption for 2026 is $15,000,000 per individual, following the increase enacted through the One, Big, Beautiful Bill Act signed in July 2025.1Internal Revenue Service. What’s New – Estate and Gift Tax The amount is permanent and will be adjusted for inflation starting in 2027. A will with a formula clause written when the exemption was $5 million or $11 million could now direct $15 million into a bypass trust, potentially leaving far less to a surviving spouse than the testator ever intended. If your will has a formula clause, have it reviewed.
A will you signed years ago is almost certainly still valid. Whether it still says what you want it to say is a different question, and it’s the one worth asking.