# Irrevocable Trust: Definition and How It Works in California

> An irrevocable trust can't be changed or revoked by the settlor once it's created, with only narrow exceptions.

Source: https://ridleylawoffices.com/estate-planning-glossary-california/irrevocable-trust/

By Eric Ridley, attorney, Ridley Law. Updated September 2026.

An **irrevocable trust** can’t be changed or revoked by the settlor once it’s created, with only narrow exceptions. That loss of control is what gives it asset protection and tax advantages a revocable trust doesn’t have.

## How it works in California

Under Prob. Code, § 15400, a trust is revocable unless the trust instrument expressly makes it irrevocable. That default rule is why most living trusts are revocable and why a trust has to say, in its own language, that it’s irrevocable for that status to apply. Working with the right kind of trust for the goal matters; see [irrevocable trust lawyer in California](https://ridleylawoffices.com/irrevocable-trust-attorney/) for how these trusts get built and used.

Once a trust is irrevocable, the settlor generally gives up the ability to take property back out of it or change its terms unilaterally. In exchange, assets properly transferred into an irrevocable trust are typically outside the settlor’s own taxable estate and are harder for the settlor’s creditors to reach, which is why these trusts show up in tax planning and asset protection work.

Narrow exceptions exist, including modification with beneficiary consent or court approval, and decanting by the trustee, but these are exceptions to the rule, not a backdoor that makes the trust functionally revocable. A settlor who expects to change their mind later should think hard before making a trust irrevocable in the first place.

## Why it matters

For example, a parent creates an irrevocable trust to hold a life insurance policy outside their taxable estate. Years later, they want to add a beneficiary the trust doesn’t currently name. Because the trust is irrevocable, that change isn’t simply a matter of signing an amendment the way it would be with a revocable trust; it may require a formal modification process or may not be possible at all. For what options actually exist once a trust is irrevocable, see [can you change an irrevocable trust in California](https://ridleylawoffices.com/changing-an-irrevocable-trust-california/).

## Common mistakes

Assuming an irrevocable trust can be amended the same way a revocable trust can. Transferring an asset into an irrevocable trust without fully understanding that the transfer is, for practical purposes, permanent. Choosing an irrevocable trust for tax or asset-protection reasons without weighing the loss of control against a family’s actual likelihood of needing that flexibility later.

## Related terms

- [Living trust](https://ridleylawoffices.com/estate-planning-glossary-california/living-trust/): the broader category that includes both revocable and irrevocable versions.
- [QTIP trust](https://ridleylawoffices.com/estate-planning-glossary-california/qtip-trust/): one specific type of irrevocable trust used for a surviving spouse.
- [Revocable trust](https://ridleylawoffices.com/estate-planning-glossary-california/revocable-trust/): the default kind of trust under Prob. Code, § 15400, and the direct contrast to an irrevocable one.
- [Special needs trust](https://ridleylawoffices.com/estate-planning-glossary-california/special-needs-trust/): typically structured as irrevocable to protect a beneficiary’s eligibility for public benefits.
- [Step-up in basis](https://ridleylawoffices.com/estate-planning-glossary-california/step-up-in-basis/): a tax benefit that can work differently for assets held in an irrevocable trust than for those in the settlor’s own name.
- [Trust decanting](https://ridleylawoffices.com/estate-planning-glossary-california/trust-decanting/): one of the narrow tools available to change an irrevocable trust’s terms.
- [Charitable Remainder Trust](https://ridleylawoffices.com/estate-planning-glossary-california/charitable-remainder-trust/): an irrevocable trust that pays income for a period, then passes the rest to charity.
- [Irrevocable Life Insurance Trust (ILIT)](https://ridleylawoffices.com/estate-planning-glossary-california/irrevocable-life-insurance-trust/): a trust that owns life insurance to keep the proceeds out of the taxable estate.
- [Spendthrift Trust](https://ridleylawoffices.com/estate-planning-glossary-california/spendthrift-trust/): a trust that keeps a beneficiary’s interest away from most creditors until it is paid out.

Part of the [California estate planning glossary](https://ridleylawoffices.com/estate-planning-glossary-california/). For the full treatment, see [Irrevocable Trust Lawyer in California](https://ridleylawoffices.com/irrevocable-trust-attorney/).