Va. Code § 58.1-1740
Credit shall be granted any rentor subject to the additional tax on the rental of a daily rental passenger car for a portion of the tangible personal property tax assessed by a Virginia locality on such car for a tax year ending after June 30, 1981. The amount of such credit shall be equal to the ratio of the number of months in such tax year after June 30 to the total number of months in the tax year. Any such credit may be carried over from month to month for a period of up to six months or until fully absorbed, whichever occurs first. To the extent any credit is claimed hereunder as to any tangible personal property tax properly assessed and not actually paid when due, such credit shall be subject to collection as an underpayment of the additional tax imposed under subdivision A 2 of § 58.1-1736 as of the date the credit was claimed, with penalties and interest as provided in § 58.1-2411, mutatis mutandis.
Va. Code § 58.1-1740