Contracts Not to Revoke a Will Under California Law

Diagram summarising contract not to revoke a will under California and federal law — Visual summary of contract not to revoke a will

Can Someone Sue Over a Broken Promise to Leave Them Property?

“Take care of me, and I’ll leave you the house” is one of the oldest promises in estate planning — and one of the most frequently broken. California takes these promises seriously. A testator can enter a binding contract to make a specific testamentary gift, or to refrain from revoking a will, and if the testator breaks that promise, the disappointed promisee has a real legal remedy.

A contract not to revoke a will (or to make one) is an ordinary contract, governed by ordinary contract-law principles, with one twist: for agreements made on or after January 1, 2000, Cal. Probate Code § 21700 imposes special proof requirements before a court will enforce it. California Bar Exam candidates should know all four proof methods cold, since essays love mixing them with joint-will facts.

Four Ways to Prove the Contract Exists

Because oral promises about inheritance are easy to fabricate after someone dies, § 21700 limits proof to four specific methods. Satisfying any one of them is enough:

The will itself states the material provisions of the contract.
The will expressly refers to the contract, and extrinsic evidence proves its terms — notably, the Statute of Frauds does not bar this evidence.
A writing signed by the decedent evidences the contract, even outside the will itself.
Clear and convincing evidence of an agreement between the decedent and the beneficiary (or between the decedent and a third party for the claimant’s benefit) — no writing required at all, if the evidence is strong enough.

That fourth method surprises a lot of people: California does not require a writing to enforce this kind of promise, as long as the proof of the agreement is clear and convincing.

Proof of the Contract Isn’t Proof of a Valid Contract

Here’s a subtlety that trips up both bar candidates and real families: satisfying one of the four § 21700 methods proves that a contract was made and what its terms were — it does not substitute for ordinary contract formation. The claimant still needs offer, acceptance, and consideration, just like in any other contract dispute. In practice, the consideration is usually the promisee’s own return promise or performance — caregiving services, a reciprocal promise in a mutual will, or forgoing some other opportunity in reliance on the decedent’s promise.

When Can the Promisee Sue?

Timing matters, and California has a default rule with one important exception:

Situation	When the Breach Claim Accrues
Standard case — testator simply doesn’t follow through	At the decedent’s death, not at the moment of breach during life
Fraud-on-the-promisee exception — decedent induced performance in reliance on the promise, then broke it while still alive	Immediately, without waiting for death

The default rule exists because, until death, a testator generally retains the right to change a will — so a promisee usually can’t sue mid-life just because the testator amended their estate plan. But if the testator actively induced someone to perform (move in as a caregiver, give up a job, provide years of service) in reliance on the promise, and then broke the promise during life rather than merely changing their mind at some point before death, the promisee doesn’t have to wait for the funeral to sue.

The Remedy: Constructive Trust

When a contract to make or not revoke a will is breached — say, the testator dies having left the promised property to someone else, or having revoked the will entirely — the typical remedy is a constructive trust. The court doesn’t rewrite the will; instead, it orders whoever actually received the property (the recipient devisee, or the estate) to hold it in trust for the promisee, who is then entitled to receive it.

This is not the only possible remedy — other contract remedies like damages or specific performance can be available depending on the facts — but constructive trust is the doctrine’s signature tool because it lets a court honor the contract without invalidating the testator’s actual, validly executed will.

Worked Example: The Caregiver’s Promise

Elena, elderly and living alone, asks her neighbor Tomás to move in and provide daily caregiving in exchange for a promise: “If you take care of me until I die, I’ll leave you my house.” Tomás moves in, provides years of caregiving, and gives up his own apartment lease in reliance. Elena never puts this in writing and never mentions it in her will, which — signed years earlier — leaves everything to her adult children.

After Elena dies, can Tomás enforce the promise? He needs one of the four § 21700 proof methods. If Elena’s will says nothing about the arrangement and there’s no signed writing from her, Tomás’s best (and possibly only) path is method four: clear and convincing evidence of the agreement — testimony from neighbors who heard Elena describe the deal, Tomás’s lease termination records timed to match his move, financial records showing he received no separate compensation, and so on. If that evidence clears the clear-and-convincing bar, a court can impose a constructive trust on the house in Tomás’s favor, even though Elena’s actual will never mentioned him and there’s no writing.

Now change the facts: suppose Elena, while still alive, sold the house and pocketed the proceeds specifically to defeat the promise, after having induced years of free caregiving from Tomás. That’s the fraud-on-the-promisee scenario — Tomás wouldn’t need to wait for Elena’s death to sue; the breach during her life is itself actionable.

Not the Same as a Joint or Mutual Will

One frequent mix-up: the mere existence of a joint or mutual will (spouses executing wills with reciprocal, mirror-image terms) does not, by itself, create a presumption of a contract not to revoke. The existence of matching wills is not one of the four proof methods — a party still has to independently satisfy one of them to establish that the spouses actually agreed to be contractually bound, not just that they happened to write similar wills.

Frequently Asked Questions

Do I need something in writing to enforce a promise that someone would leave me property in their will?

Not necessarily. Cal. Probate Code § 21700 allows proof through clear and convincing evidence of the agreement, even without any writing — though a writing makes the case significantly easier to prove.

When can I sue if someone broke their promise to leave me property?

Generally, only after the promisor’s death. The exception is if the promisor induced you to perform in reliance on the promise and then broke it during their lifetime — in that case, you can sue immediately.

What do I actually get if I win a case like this?

Usually a constructive trust: the court orders whoever received the property to hold it in trust for you and transfer it to you, rather than rewriting the decedent’s will itself.

Key Takeaways

California enforces contracts to make or not revoke a will, governed by ordinary contract law plus special proof rules under Cal. Probate Code § 21700 (agreements on or after January 1, 2000).
Any one of four proof methods suffices, including clear and convincing evidence of an agreement even without a writing.
Proving the contract’s existence under § 21700 doesn’t replace the need for actual offer, acceptance, and consideration.
The breach claim generally accrues at death, except for the fraud-on-the-promisee exception, which allows suit during the decedent’s life.
The typical remedy is a constructive trust imposed on whoever actually received the property.

Related guides

Sources and further reading

This article is educational and is not legal advice. Consult a licensed California attorney about your situation.