72 Pa. Stat. § 8226-A
The department may at its discretion require that any or all returns, reports or registrations that are required to be filed under this article be filed electronically. Failure to electronically file any return, report, registration or other information the department may direct to be filed electronically shall subject the taxpayer to a penalty of 5% of the tax due on the return, up to a maximum of $1,000, but not less than $10. This penalty shall be assessed at any time and collected in the manner provided in this article. This penalty shall be in addition to any civil penalty imposed in this article for failure to furnish information or file a return. The criminal penalty for failure to file a return electronically shall be the same as the criminal penalty for failure to furnish information or file a return under this article.
72 P.S. § 8226-A