26 CFR § 41.6109-2
Tax return preparers furnishing identifying numbers for returns or claims for refund filed after December 31, 2008
June 25, 2020
(a) In general. Each excise tax return or claim for refund under section 4481 prepared by one or more signing tax return preparers must include the identifying number of the preparer required by §1.6695-1(b) of this chapter to sign the return or claim for refund in the manner stated in §1.6109-2 of this chapter.
(b) Effective/applicability date. This section is applicable for returns and claims for refund filed after December 31, 2008.
[T.D. 9436, 73 FR 78455, Dec. 22, 2008]