41 C.F.R. § 105-56.031 – Notice.

(a) The disbursing official will provide GSA an electronic list of the names, mailing addresses, and taxpayer identifying numbers of the debtors from whom amounts of past-due, legally enforceable debt are due other Federal agencies. The disbursing official will identify the creditor agency name and a point of contact that will handle concerns regarding the debt.
(b) Before offsetting a salary payment, the GSA National Payroll Center, acting as the paying agency on behalf of the disbursing official, will notify the debtor in writing of the date deductions from salary will commence and of the amount of such deductions.
(c)
1. (1) When an offset occurs under this subpart, the disbursing official, or the GSA National Payroll Center on behalf of the disbursing official, will notify the debtor in writing that an offset has occurred including—
  1. (i) A description of the payment and the amount of offset taken;
  2. (ii) The identity of the creditor agency identified by the disbursing official requesting the offset; and
  3. (iii) A contact point at the creditor agency identified by the disbursing official that will handle concerns regarding the offset.
2. (2) The information described in paragraphs (c)(1)(ii) and (c)(1)(iii) of this section does not need to be provided to the debtor when the offset occurs if such information was included in a prior notice from the disbursing official or the creditor agency.