Pennsylvania Statutes Title 72 P.S. Taxation and Fiscal Affairs § 10003.21. Further examination of books and records

(a) The Department of Revenue or any of its authorized agents is authorized to examine the books, papers and records of any taxpayer or other persons in order to verify the accuracy and completeness of a return or report or, if no return or report is made, to ascertain and assess any tax or other liability owed the Commonwealth.

(b) The department may determine, by desk, field or other audit, the amount of tax or other liability required to be paid to the Commonwealth.  The department may determine the liability based upon the facts contained in the return or report being audited or upon other information in the department's possession.  The department may determine the liability based upon a reasonable statistical sample or test audit performed in accordance with the regulations of the department if the individual being audited does not have complete records of transactions or if the review of each transaction or invoice would place an undue burden on the department to conduct an audit in a timely and efficient manner.

(c) The taxpayer may challenge the accuracy of a statistical sample or test audit by providing clear and convincing evidence that the method used for the statistical sample or test audit is erroneous, lacks a rational basis or produces a different result when the complete records are considered.