Va. Code § 58.1-3910.1
Notwithstanding any other provision of law, the Loudoun County Board of Supervisors may authorize the treasurer of Loudoun County to enter into an agreement with any town located partially or wholly within Loudoun County for the county treasurer to collect and enforce delinquent or non-delinquent real or personal property taxes owed to such town. The county treasurer collecting town taxes pursuant to an agreement made under this section shall account for and pay over to the town the amounts collected, as provided by law. Any such agreement shall establish the terms for such collection and enforcement, including payment of reasonable compensation by the town for the services of the county treasurer and the order in which the county treasurer will credit partial payments between taxes owed to the county and those owed to the town.
Va. Code § 58.1-3910.1