(a) On receipt of a request for issuance of an order or writ of withholding, the clerk of the court shall deliver a certified copy of the order or writ to the obligor's current employer or to any subsequent employer of the obligor. The clerk shall attach a copy of Subchapter E to the order or writ.
(b) Not later than the fourth working day after the date the order is signed or the request is filed, whichever is later, the clerk shall issue and deliver the certified copy of the order or writ by:
(1) certified or registered mail, return receipt requested, to the employer; or
(2) service of citation to:
(A) the person authorized to receive service of process for the employer in civil cases generally; or
(B) a person designated by the employer by written notice to the clerk to receive orders or notices of income withholding.