As mandated by the Office of Child Support Services, if an Income Withholding Order is sent by a private attorney or other person, an employer must also receive a copy of the underlying administrative or court order containing a provision authorizing withholding.
As mandated by the Internal Revenue Service, every withholding agent who has control, custody, or receipt of amounts subject to withholding files Form 1042-S, Foreign Person's U.S. Source Income Subject to Withholding on an annual basis.