Va. Code § 15.2-620
The director of finance shall exercise the powers conferred and perform the duties imposed by general law upon county treasurers, and shall be subject to the obligations and penalties imposed by general law. All moneys received by any county officer or employee for or in connection with county business shall be paid promptly into the hands of the director of finance. All such money shall be promptly deposited by the director of finance to the credit of the county in such banks or trust companies the board selects. No money shall be disbursed or paid out by the county except upon check signed by the chairman of the board, or such other person the board designates, and countersigned by the director of finance.
The director of finance or his authorized deputies may transfer public funds from one depository to another by wire. Such officers may also draw any of the county's money by check or by an electronic fund wire, or by any means deemed appropriate and sound by the director of finance and approved by the board, drawn upon a warrant issued by the board. If any money is knowingly paid otherwise than upon the director of finance's check or electronic fund wire or by alternative means specifically approved by the director of finance and the board, drawn upon such warrant, the payment shall be invalid against the county.
The board may designate one or more banks or trust companies as a receiving or collecting agency under the direction of the department of finance. All funds so collected or received shall be deposited to the credit of the county in such banks or trust companies as the board selects.
Every bank or trust company serving as a depository or as a receiving or collecting agency for county funds shall be required by the board to give adequate security therefor, and to meet such requirements as to interest thereon as the board may establish. All interest on money so deposited shall accrue to the benefit of the county.
Va. Code § 15.2-620