ERO /ERO.html This page describes the process of filing returns using 941Express as an Electronic Returns Originator. Reporting Agent Pub 3823 941 e-file 940 e-file transmitter ero electronic returns originator this option is no longer valid within the payroll e-file program in the past, it was possible for a tax professional to use 941express as an ero and obtain pin numbers from their customers to e-file returns the irs no longer allows this type of activity in other words, if an business obtains a 10 digit pin for e-filing payroll returns, they cannot provide that pin to a tax preparer for the purpose of filing their return if the tax preparer wants to file this return for them, they must become their reporting agent and register for their own 5 digit reporting agent pin the business can however file this return themselves with their own 10 digit pin without issue that scenario is the business taxpayer or preparer option