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 Wisconsin, 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 out of the grantor's possession and control. This transfer of ownership can provide certain tax advantages, as the assets are no longer considered part of the grantor's estate for estate tax purposes. Wisconsin statutes, along with federal law, govern the creation and administration of irrevocable trusts, and these laws dictate how the trust must be managed and how the assets are to be distributed to the beneficiaries. It is important to note that while the trust is generally irrevocable, there may be provisions under state law that allow for modifications or termination under specific circumstances, such as with the agreement of all beneficiaries or by court order if certain conditions are met.