Va. Code § 58.1-305
Every commissioner of the revenue shall obtain an income tax return from every individual or fiduciary within his jurisdiction who is liable under the law to file such a return with him; provided such individual or fiduciary has not filed such a return with the Department of Taxation. This duty of the commissioner of the revenue to obtain such return shall in no manner diminish any obligation to file a return without being called upon to do so by the commissioner of the revenue or any other officer. Each commissioner of the revenue shall audit returns as soon as practicable after they are made to him and shall assess the amount of taxes, or the amount of additional taxes, as the case may be, which appears to be due. Such auditing shall not be done in a manner or at a time in any case as will result in any delay on the part of the commissioner of the revenue in complying with §§ 58.1-307 and 58.1-350.
Va. Code § 58.1-305