Section 20.6694-1 - Section 6694 penalties applicable to tax return preparer(a)In general. For general definitions regarding section 6694 penalties applicable to preparers of estate tax returns or claims for refund, see § 1.6694-1 of this chapter.(b)Effective/applicability date. Paragraph (a) of this section is applicable to returns and claims for refund filed, and advice provided, after December 31, 2008.T.D. 9436, 73 FR 78450, Dec. 22, 2008, as amended at 74 FR 5105, Jan. 29, 2009