Implements § 6601Open in workspace
Reg. § 53.6601-1 Interest on underpayment, nonpayment, or extensions of time for payment, of tax.
26 CFR § 53.6601-1eCFR, current through 2026-07-14
For regulations concerning interest on underpayment, nonpayment, or extensions of time for payment of tax, see (Regulations on Procedure and Administration).