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 Connecticut (CT), an irrevocable trust is a type of trust that, once established, typically cannot be changed, modified, or terminated by the person who created it, known as the grantor, settlor, or trustor, without the consent of the trust's beneficiaries. The main characteristic of an irrevocable trust is the transfer of ownership of assets from the grantor to the trust, which is managed for the benefit of the beneficiaries. This transfer is considered complete and permanent, which can provide certain tax advantages, such as reducing the grantor's taxable estate. Because the assets are no longer owned by the grantor, they are generally not subject to estate taxes upon the grantor's death. Connecticut law, like the law in many states, presumes that a trust is revocable unless the trust instrument explicitly states it is irrevocable. It's important to note that while irrevocable trusts are more rigid in structure compared to revocable trusts, under certain circumstances and with proper legal procedures, modifications can sometimes be made with the agreement of the beneficiaries or by court order.