We are not aware of any recent changes to the rules governing Employer Identification Numbers (EINs) for grantor trusts. Whether you need to obtain an EIN for a grantor trust depends on how the trust’s tax return is filed. The instructions for the estate tax return, Form 1041, state that every trust that is required to file Form 1041 must have an EIN. Form 1041 Instructions, Employer Identification Number. However, some trusts are not required to file Form 1041 returns. For example, if a trust is considered a “grantor trust,” it is not required to file a Form 1041, and we would assume that the grantor’s social security number would suffice for that type of trust. Form 1041 Instructions, Optional Filing Methods for Certain Grantor Type Trusts.