Periodic Returns. Semi-weekly (Form MW-5) according to the federal semi-weekly deposit requirements if more than $1,500 was withheld in previous quarter and employer is on a semi-weekly federal deposit schedule. Monthly (Form MW-5) by 15th day of following month if total withheld tax for the previous quarter was more than $1,500 and employer is on a monthly federal deposit schedule. Quarterly (Form MW-1) by last day of month following end of the first three calendar quarters by all employers, except annual filers, and with the deposit if the employer is not on a semi-weekly or monthly deposit schedule; Form MW-5 by January 31 with the last quarter's deposit or Form MW-6 if filed with the fourth quarter's deposit by January 31. Annually (Form MW-1A by February 28 if $1,500 or less withheld in the last four quarters.
Annual Reconciliation Returns. Form MW-6 due February 28; annual filers need not file this form.
Timely Filing. If any returns or reports become due on a Saturday,
Sunday, or legal holiday, returns shall be considered timely if performed on the
next succeeding day that is not a Saturday, Sunday, or legal holiday. Payments,
returns, or deposits are treated as timely if made on the earlier of (1) the
date received by the department; or (2) the date of mailing, but only if mailed
on or before the day prior to the due date. The person required to make the
payment, return, or deposit has the burden of establishing that it was mailed in
the U.S. by U.S. mail in an envelope or other appropriate wrapper, postage
prepaid, and properly addressed.