IRS Publication 1220 cover these forms 1097, 1098, 1099, 3921, 3922, 5498, 8935, and W-2G and the corresponding electronic filing.  The mailing deadline for these forms is January 31.  Once your account is authorized you must select between 3 possible processing cycles in January.

 

 

IRS Publication 1187 covers 1042 forms.

The statutory mailing deadline for 1042-S statements is March 15 each year.  You may upload these files at any time (when your account is authorized to do so), but these files will be processed after January and the 1042-S statements will be mailed on or before

March 15th.

 

For more information on these publications please visit www.irs.gov.