Both travel on the same procedural machinery, which is why they get conflated. A Heggstad petition is brought under Prob. Code § 850, the statute allowing an order where a trust claims property held by another. The doctrine comes from Estate of Heggstad (1993) 16 Cal.App.4th 943, holding that where the settlor declared himself trustee of his own property, a written signed declaration of trust identifying the property was itself enough to create the trust in that real property, with no separate deed. Ukkestad v. RBS Asset Finance, Inc. (2015) 235 Cal.App.4th 156 extended that to a general clause covering all of the settlor's real and personal property wherever situated, and Carne v. Worthington (2016) 246 Cal.App.4th 548 applied the same reasoning to a later trust's schedule moving property out of an earlier one. A modification petition, by contrast, rests on Prob. Code § 15403 or § 15409, and both petitions reach the judge through Prob. Code § 17200. Filing the wrong one wastes months, because the court will not reform a document you actually needed confirmed, or confirm title you actually needed rewritten.
Fixing or Changing a Trust · California
How is a trust modification petition different from a Heggstad petition?
They ask the probate court two entirely different questions. A Heggstad petition asks the court to confirm that an asset was already trust property — that nothing needs to change, because the settlor's signed declaration of trust already captured the house or the account even though the deed or the title never got updated. A trust modification petition asks the court to change the trust's terms — to alter what the document actually says or how it operates going forward. One is about ownership, the other is about text. The practical test is simple: if your problem is that the right asset is sitting outside the trust, you have a funding problem and you are on the Heggstad side. If your problem is that the trust itself says the wrong thing or has become unworkable, you have a drafting or circumstances problem and you are on the modification side. The same family can genuinely need both, filed together.
This page is general information about California law, not legal advice, and does not create an attorney-client relationship. Figures and deadlines change, and every family’s situation is different. Last reviewed August 2026.
Related Questions
The questions this one leads to.
Can a mistake in a trust be fixed after the person who made it has died?
Often, yes. How California courts correct a trust mistake after the settlor dies, and why a funding defect and a drafting defect need different petitions.
Read the answerThe trust says one thing and the will says another — which controls?
Neither overrides the other. A California trust governs trust assets and the will governs what was left in the decedent's name. How the pour-over will fits.
Read the answerCan an irrevocable trust be changed in California?
Yes, in defined circumstances. The three California routes to change an irrevocable trust, who has to sign each one, and when a judge has to approve it.
Read the answerNext Step
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