26 C.F.R. § 301.7515-1
The Commissioner is authorized within his discretion, upon written request of any person and payment by such person of the cost of the work to be performed, to make special statistical studies and compilations involving data from returns, declarations, statements, or other documents required by the Code or regulations or from records established or maintained in connection with the administration and enforcement of the Code; to engage in any such special study or compilation jointly with the party or parties requesting it; and to furnish transcripts of any such study or compilation. The requests for services should be addressed to the Commissioner of Internal Revenue, Attention: PR, Washington, D.C. 20224. The requests should describe fully the nature of the study or compilation desired, giving detailed specifications for all tables to be prepared, and should include a general statement regarding the use to be made of the data requested.
26 C.F.R. §301.7515-1