(a) The Title IV-D agency may initiate income withholding by issuing an administrative writ of withholding for the enforcement of an existing order as authorized by this subchapter.
(b) Except as provided by Subsection (d), the Title IV-D agency is the only entity that may issue an administrative writ under this subchapter.

(c) The Title IV-D agency may use the procedures authorized by this subchapter to enforce a support order rendered by a tribunal of another state regardless of whether the order has been registered under Chapter 159.
(d) A domestic relations office may issue an administrative writ of withholding under this chapter in a proceeding in which the office is providing child support enforcement services. A reference in this code to the Title IV-D agency that relates to an administrative writ includes a domestic relations office, except that the writ must be in the form prescribed by the Title IV-D agency under § 158.504.