A. In accordance with procedures established by the Tax Commissioner, any corporation may elect an extension of time within which to file the income tax return required under this chapter to the date six months after such due date or 30 days after the extended date for filing the federal income tax return, whichever is later, provided that the estimated tax due is paid in accordance with the provisions of subsection B.
B. Any taxpayer desiring an extension of time in accordance with the provisions of subsection A shall, on or before the original due date for the filing of such return, in accordance with the procedures established by the Tax Commissioner pay the full amount properly estimated as the balance of the tax due for the taxable year after giving effect to any estimated tax payments under § 58.1-491 and any tax credit under § 58.1-499. If any amount of the balance of the tax due is underestimated, interest at the rate prescribed in § 58.1-15 will be assessed on such amount from the original due date for filing of the income tax return to the date of payment. In addition to interest, if the underestimation of the balance of tax due exceeds 10 percent of the actual tax liability, there shall be added to the tax as a penalty an amount equal to two percent per month for each month or fraction thereof from the original due date for the filing of the income tax return to the date of payment.
C. If the return is not filed, or the full amount of the tax due is not paid, on or before the extended due date elected under subsection A, the penalty imposed by § 58.1-450 or 58.1-455 shall apply as if no extension had been granted.