Section 143.591, RSMo, requires employers with 250 or more employees to submit the Form MO W-3 and accompanying Form W-2’s electronically;

  • The file must follow the Social Security Administration's EFW2 format along with Missouri modifications as outlined in theMissouri Employer Reporting of W-2s Instructions and Specifications. This publication will be published at a later date.
  • The file must be submitted by January 31.

Instructions for filing electronic W-2s for tax year 2018 will be made available later in the year. Please check back periodically for new information.

1099 Reporting

While it is not statutorily required for employers to provide their 1099 files electronically, beginning 2018 for tax year 2017, Missouri will be accepting those files through the same type of bulk upload process being utilized for W-2 reporting.

The Missouri 1099 Reporting Requirements and Specification Handbookis designed to be used as a companion to the Internal Revenue Service Publication 1220. The handbook highlights the special requirements of the Missouri electronic filing program. The handbook will be published at a later date.