Section 551.7 - Calculation of funds for recipient executive agencies(a) The Postal Service is to determine its reasonable costs in executing its responsibilities pursuant to the Semipostal Authorization Act, as specified in § 551.8 . These costs are offset against the revenue received through sale of each semipostal stamp in excess of the First-Class Mail single-piece first-ounce rate in effect at the time of purchase.(b) Any reasonable costs offset by the Postal Service shall be retained by it, along with revenue from the sale of the semipostal stamps, as recorded by sales units through the use of a specially designated account.(c) The Postal Service is to pay designated recipient executive agency(ies) the remainder of the differential revenue less an amount to recover the reasonable costs of the Postal Service, as determined under § 551.8 .(d) The amounts for recipient executive agencies are transferred in a manner and frequency determined by mutual agreement, consistent with the requirements of 39 U.S.C. 416 .