How can an employer or payer report changes on previously-filed electronic media submission of informational returns?
Any changes to files submitted electronically must be done using the paper method. Once Form CT-W3 or CT-1096 has been successfully filed and a confirmation number has been issued, you will no longer have the option to return to file or correct informational returns. If a particular form is omitted, that form must be sent in on paper in addition to a corrected paper Form CT-W3 or CT-1096.