31 U.S.C. § 3322

1. (a)The Secretary of the Treasury shall transfer public money to a disbursing official only by draft or warrant written on the Treasury. Except as provided in section 3716 and section 3720A of this title and subsection (b) of this section, a disbursing official shall—
   1. (1)deposit public money as required by section 3302 of this title; and
   2. (2)draw public money from the Treasury or a depositary only—
      1. (A)as necessary to make payments; and
      2. (B)payable to persons to whom payment is to be made.
2. (b)In a place without a depositary, the Secretary, on deciding it is essential to the public interest, may authorize specially in writing that public money be—
   1. (1)deposited in any other public depositary; or
   2. (2)kept in another manner under regulations the Secretary decides are the safest and most effective in making a payment to a public creditor easier.
3. (c)A disbursing official is not liable for an overpayment provided under a United States Government bill of lading or transportation request when the overpayment is caused by the—
   1. (1)use of improper transportation rates or classifications if the Administrator of General Services has determined that verification by a prepayment audit conducted pursuant to section 3726(a) of this title for a particular mode or modes of transportation, or for an agency or subagency, will not adequately protect the interests of the Government; or
   2. (2)failure to deduct the proper amount under—
      1. (A)a land grant law; or
      2. (B)an equalization or other agreement.