Trust accounts are designed to transfer wealth from a grantor to a beneficiary. There are many types of trust. Whether a trust needs a tax ID depends on the type of trust it is. A revocable, living trust remains under control of the grantor of the trust, and because of this it doesn’t need a tax ID. Instead, the trust will use the same tax ID as the grantor.
On the other hand, if the trust is an irrevocable trust, it’s no longer under the direct control of the grantor. In fact, the grantor cannot make changes to the trust without the permission of the beneficiaries. These trusts do need their own EIN, because they are a separate entity from the grantor.
Even with a revocable trust, an EIN may eventually be needed. Once the grantor passes on, the revocable trust will become an irrevocable trust, and it will need its own EIN. Some trust funds are going to be taxed under their own EIN, while other trusts are going to be taxed to the beneficiary instead. This depends on the way that the trust has been formed.