Periodic Returns. Form WH-1 by the 30th day following the end of the applicable period: quarterly if average monthly amount withheld does not exceed $75; semi-annual if average monthly amount withheld does not exceed $25; annual if average monthly amount withheld does not exceed $10; monthly if average monthly amount withheld does not exceed $1,000; monthly within 20 days after end of the month if the average monthly amount withheld exceeds $1,000; employers can also be required to file monthly if the average monthly amount withheld for the current year is estimated to be $1,000. If an employer's estimated monthly withholding tax for the current year or its average monthly withholding tax for the preceding year exceeds $20,000, the employer must remit the monthly withholding taxes due by electronic fund transfer or by delivering in person or by overnight courier a payment by cashier's check, certified check, or money order to the department. The transfer or payment must be made on or before the date the remittance is due.
Annual Reconciliation Returns. Form WH-3 due by February 28.
Timely Filing. If the due date for filing a return or report falls on
a Saturday, Sunday, or legal holiday, the filing date is extended to midnight of
the following business day. A return will be deemed filed if (1) postmarked the
day it is due, or (2) where it is delivered to the department in a manner other
than through the mail on the date it is physically received by the department.
If a return is mailed to, but not received by, the department, the person who
mailed the return will be deemed to have filed the return on or before the due
date if he can show by reasonable evidence that the return was mailed on or
before the due date and if he files a duplicate return within 30 days after the
department sends notice that the return was not filed.