Virginia Code Title 58.1. Taxation § 58.1-416. When certain other sales deemed in the Commonwealth

A. Sales, other than sales of tangible personal property, are in the Commonwealth if:

C. The taxes under this article on the sales described under subsection B are imposed to the maximum extent permitted under the Constitutions of Virginia and the United States and federal law. For the collection of such taxes on such sales, it is the intent of the General Assembly that the Tax Commissioner and the Department assert the taxpayer's nexus with the Commonwealth to the maximum extent permitted under the Constitutions of Virginia and the United States and federal law.

D. If necessary information is not available to the taxpayer to determine whether a sale other than a sale of tangible personal property is in the Commonwealth pursuant to the provisions of subsections B and C, the taxpayer may estimate the dollar value or portion of such sale in the Commonwealth, provided that the taxpayer can demonstrate to the satisfaction of the Tax Commissioner that (i) the estimate has been undertaken in good faith, (ii) the estimate is a reasonable approximation of the dollar value or portion of such sale in the Commonwealth, and (iii) in using an estimate the taxpayer did not have as a principal purpose the avoidance of any tax due under this article. The Department may implement procedures for obtaining its approval to use an estimate. The Department shall adopt remedies and corrective procedures for cases in which the Department has determined that the sourcing rules for sales other than sales of tangible personal property have been abused by the taxpayer, which may include reliance on the location of income-producing activity and direct costs of performance as described in subsection A.