(a) In general. For rules relating to the extension of the period of collection when a tax return preparer who prepared a return or claim for refund of the section 2801 tax pays 15 percent of a penalty for understatement of taxpayer's liability, and for procedural matters relating to the investigation, assessment, and collection of the penalties under section 6694(a) and (b) of the Code, the rules under § 1.6694-4 of this chapter apply.

(b) Applicability date. This section applies to returns and claims for refund filed, and advice provided, on or after January 14, 2025.