Va. Code § 63.2-1951
The Department shall pay interest to the payee as provided in this section on certain spousal or child support payments it collects which have been ordered by a court or established by administrative order to be paid to or through the Department to the payee and for which the Department has an assignment of rights or has been given an authorization to seek or enforce a support obligation as those terms are defined in §§ 63.2-100 and 63.2-1900. Such interest shall accrue, at the legal rate as established by § 6.2-301, on all support payments collected by the Department and paid to the payee more than thirty days following the end of the month in which the payment was received by the Department in nonpublic assistance cases. Interest shall be charged to the Department on such payments if the Department has an established case and if the obligor or payor provides identifying information including the Department case number or the noncustodial parent's name and correct social security number.
Va. Code § 63.2-1951