An irrevocable trust is a trust that cannot be amended, modified, or terminated by the grantor, settlor, or trustor (person who created the trust) after it is created—at least not without the permission of the beneficiary or beneficiaries.

Irrevocable trusts generally offer tax benefits that revocable trusts do not. This is primarily because the grantor, settlor, or trustor who creates an irrevocable trust permanently transfers (gifts) all right of ownership of the assets to the trust and its beneficiaries.

Laws vary from state to state but a trust is usually irrevocable unless the grantor, settlor, or trustor specifies otherwise in the trust agreement.

In Iowa, an irrevocable trust is a type of trust that, once established, cannot be altered, amended, or terminated by the grantor without the consent of the beneficiaries. The assets placed into the trust are permanently transferred to the trust and are no longer considered the property of the grantor. This transfer of ownership can provide certain tax advantages, as the assets may no longer be part of the grantor's taxable estate. Iowa law requires that the terms of the trust must be clearly stated in the trust agreement, and by default, a trust is considered irrevocable unless the trust agreement specifies that it is revocable. It's important to note that while the grantor cannot change the trust, under certain circumstances, beneficiaries may have the power to modify the trust with the appropriate legal and court procedures.