General rule. For purposes of making the claim for credit or refund under § 48.6412-1 in respect of floor stocks held by a dealer, the tax paid on each article must be separately computed. If desired, the procedures set forth in paragraphs (b) through (g) of this section may be used in making the computation. The procedure used in determining the tax paid on an article must also be used in determining the amount of tax, if any, made applicable to the article on the effective date of reduction or repeal of the tax involved. Prior approval of the Internal Revenue Service for the method of computation need not be obtained and should not be requested.

Selling price. In determining the price of an article on which the tax paid is to be computed, the average of the gross selling prices of identical articles sold during a representative period may be used. For example, truck chassis of the same model that are sold by the manufacturer with the same equipment and accessories are identical articles whose selling prices may be computed on the basis of an average.

Transportation charges. In determining the price of an article on which the tax paid is to be computed, the average of the exclusions authorized by section 4216(a) for transportation, delivery, insurance, installation, etc., for a reasonable category of articles during a representative period may be used.

Credits for tax paid on inner tubes. The average of the credits authorized by section 6416(c) for tax paid on tires or inner tubes may be averaged for a reasonable category of articles during a representative period. The credits shall be subtracted from the gross excise tax to arrive at the net excise tax paid.

Price readjustments. (1) In determining the price on which the tax paid is to be computed, there must be taken into account any price readjustments with respect to which the manufacturer has filed a claim for credit or refund under section 6416(b). Other price readjustments which have been, or are reasonably expected to be, made with respect to the article may, at the option of the manufacturer, be taken into account in computing the price of the article.

Price readjustments which cannot be attributed to specific articles as of the inventory date (as, for example, a price readjustment of a flat dollar amount which is made to dealers who meet a sales quota) may be taken into account on the basis of an average of the adjustments which is computed for a reasonable category of articles over a representative period.

Price readjustments related to specific items (as, for example, an automatic rebate of a specific percentage of the price of each unit sold to a dealer) may not be averaged, and in such a case only the actual price readjustment attributable to a particular article may be taken into account in computing the tax on that article.

If, because of the facts in a case, a price readjustment can be attributed to specific articles for purposes of consumer refunds but cannot be attributed to specific articles for purposes of floor stocks credits or refunds, the price adjustment may be averaged for purposes of both consumer refunds and floor stocks credits and refunds.

Representative period. A period will be considered a representative period if—

It covers (i) at least four consecutive calendar quarters, the last of which ends with a period of six calendar months immediately preceding the effective date of the tax reduction or repeal involved or (ii) any other period of time which the taxpayer can demonstrate constitutes a representative period for the particular category, and

The number of articles in the category involved sold by the manufacturer during the period either (i) equals or exceeds the number of articles in the category to which the average amount is to be applied or (ii) can be demonstrated by the taxpayer to be a representative quantity.

Reasonable category. Examples of a reasonable category of articles are articles that are identified by a common stock or class number or which are of the same model, class, or line. For the purpose of averaging exclusions, another example of a reasonable category of articles is a grouping of articles that are shipped in the same container. If a manufacturer sells articles bearing his own trademark and also sells articles as private brands, separate computations of the two brands must be made under this section.