26 CFR 20.6601-1 - Interest on underpayment, nonpayment, or extensions of time for payment, of tax.

Regulations most recently checked for updates: Aug 27, 2025

§ 20.6601-1 - Interest on underpayment, nonpayment, or extensions of time for payment, of tax.

For regulations concerning interest on underpayments, etc., see § 301.6601-1 of this chapter (Regulations on Procedure and Administration).