Question: does an irrevocable grantor trust need a tax id number?
Answer: When a trust becomes irrevocable, such as upon the death of the grantor, it will require a separate EIN. ... That TIN may be a separate EIN, or, if the trust is a grantor trust as to a beneficiary under section 678, it could use the beneficiary's TIN (typically their SSN) as the TIN for the trust.