Postage rates on first class mail

§ 4253. Postage rates on first class mail (a) Postage on first class mail is computed separately on each letter or piece of mail. The rate of postage on first class mail is four cents for each ounce or fraction of an ounce, except that the rate— (1) on drop letters is three cents for each ounce or fraction of an ounce; (2) for each single postal card and each portion of a double postal card, including the cost of manufacture, is three cents; (3) for each post card and the initial portion of each double post card conforming to section 4251 (c) of this title is three cents. (b) The rate of postage on business reply mail is the regular rate prescribed in subsection (a) of this section together with an additional charge thereon of two cents for each piece weighing two ounces or less and five cents for each piece weighing more than two ounces. The postage and charge shall be collected on delivery.