I assume you have a PTIN number that authorizes you receive payments for preparing taxes. If you are working for a tax prep company you efile under their EFIN number. If you are independent, no software will allow you to file only with your PTIN. The IRS mandates that a paid preparer who prepares over 10 tax returns must have a PTIN. If you only paper-file, EFIN is not needed, but you must sign the returns.