26 CFR § 301.6659-1 - Applicable rules.
(a) Additions treated as tax. Except as otherwise provided in the Code, any reference in the Code to “tax” shall be deemed also to be a reference to any addition to the tax, additional amount, or penalty imposed by chapter 68 of the Code with respect to such tax. Such additions to the tax, additional amounts, and penalties shall become payable upon notice and demand therefor and shall be assessed, collected, and paid in the same manner as taxes.
(b) Additions to tax for failure to file return or pay tax. Any addition under section 6651 or section 6653 to a tax shall be considered a part of such tax for the purpose of the assessment and collection of such tax. For applicability of deficiency procedures to additions to the tax, see paragraph (c) of this section.
(c) Deficiency procedures -
(1) Addition to the tax for failure to file tax return.
(i) Subchapter B, chapter 63, of the Code (deficiency procedures) applies to the additions to the income estate, gift, and chapter 41, 42, 43, and 44 taxes imposed by section 6651 for failure to file a tax return to the same extent that it applies to such taxes. Accordingly, if there is a deficiency (as defined in section 6211) in the tax (apart from the addition to the tax) where a return has not been timely filed, deficiency procedures apply to the addition to the tax under section 6651. If there is no deficiency in the tax where a return has not been timely filed, the addition to the tax under section 6651 may be assessed and collected without deficiency procedures.
(ii) The provisions of paragraph (c)(1)(i) of this section may be illustrated by the following examples:
(2) Additions to the tax for negligence or fraud. Subchapter B of chapter 63 (deficiency procedures) applies to all additions to the income, estate, gift, and chapter 41, 42, 43, and 44 taxes imposed by section 6653 (a) and (b) for negligence and fraud.
(3) Additions to tax for failure to pay estimated income taxes -
(i) Return filed by taxpayer. The addition to the tax for underpayment of estimated income tax imposed by section 6654 (relating to failure by individuals to pay estimated income tax) or section 6655 (relating to failure by corporations to pay estimated income tax) is determined by reference to the tax shown on the return if a return is filed. Therefore, such addition may be assessed and collected without regard to the provisions of subchapter B of chapter 63 (deficiency procedures) if a return is filed since such provisions are not applicable to the assessment of the tax shown on the return. Further, since the additions to the tax imposed by section 6654 or 6655 are determined solely by reference to the amount of tax shown on the return if a return is filed, the assertion of a deficiency with respect to any tax not shown on such return will not make the provisions of subchapter B of chapter 63 (deficiency procedures) apply to the assessment and collection of any additions to the tax under section 6654 or 6655.
(ii) No return filed by taxpayer. If the taxpayer has not filed a return and his entire income tax liability is asserted as a deficiency to which the provisions of subchapter B of chapter 63 apply, such provisions likewise will apply to any addition to such tax imposed by section 6654 or 6655.