31 U.S.C. § 3327 — General authority to issue checks and other drafts

(a) The Secretary of the Treasury may issue a check or other draft on public money in the Treasury to pay an obligation of the United States Government. When the Secretary decides it is convenient to a public creditor and in the public interest, the Secretary may designate a depositary to issue a check or other draft on public money held by the depositary to pay an obligation of the Government. As directed by the Secretary, each depositary shall report to the Secretary on public money paid and received by the depositary. (b) The Secretary of the Treasury shall take such actions as are necessary to ensure that Social Security account numbers (including derivatives of such numbers) are not visible on or through unopened mailings of checks or other drafts described in subsection (a) of this section.