W-2 Reporting
Employers filing 50 or more W-2 forms must submit the file in a "machine-readable form." The term "machine-readable form" includes file uploads through MassTaxConnect and electronic data transfer. The Department will no longer accept W-2 information on diskette, magnetic tape or cartridge 18-track magnetic media.

The W-2 Handbook  pdf format of W-2 Handbook
will provide you with all the information you need to know to submit your W-2 file.

Wage Reporting
The Massachusetts wage reporting system is authorized by Massachusetts General Laws, Chapter 62E, and is administered by the Department of Unemployment Assistance (DUA). Employers, including employers who do not have unemployment tax obligations, must file their quarterly wage reports via DUA's QUEST system beginning in January 2010. Visit www.mass.gov/uima for more information.

Does Massachusetts require use of the state issued tax account ID number when reporting W2 wages?
The state issued WTH account ID is proprietary to MassTaxConnect, and employer’s online tax accounts and should NOT be used when reporting W2 Reports. Transmitters of W2 Reports obligated to file with Massachusetts should always use Federal Employer Identification Number (FEIN) when asked for a state ID when submitting reports.