The Wisconsin WT-6 withholding deposit report is filed electronically with the Department of Revenue, and the deadline depends on whether the department has assigned you a semi-monthly, monthly, or quarterly schedule. You report the total Wisconsin income tax withheld for the period and pay in the same session, most commonly through My Tax Account.
When the WT-6 Is Due
Your assigned filing frequency controls every deadline. The department sets it when you register and notifies you in writing whenever it changes; a new frequency takes effect January 1 of the following calendar year.1Wisconsin Department of Revenue. Withholding Tax Guide
- Semi-monthly filers. For wages paid the 1st through the 15th, the deposit is due by the last day of the same month. For wages paid the 16th through month-end, the deposit is due by the 15th of the following month.1Wisconsin Department of Revenue. Withholding Tax Guide
- Monthly filers. Each month’s withholding is due by the last day of the following month. January withholding, for example, is due by February 28.2Wisconsin Department of Revenue. General Withholding Tax Questions
- Quarterly filers. Deposits are due April 30, July 31, October 31, and January 31.1Wisconsin Department of Revenue. Withholding Tax Guide
When a due date falls on a weekend or state-recognized holiday, it moves to the next business day.2Wisconsin Department of Revenue. General Withholding Tax Questions An ACH debit initiated through My Tax Account must be started by 4:00 p.m. Central time on the due date to count as timely.1Wisconsin Department of Revenue. Withholding Tax Guide
Extensions are narrow. The department grants a 30-day extension only for employers in a federally declared disaster area — not for software issues, staffing gaps, or cash flow problems. Disaster-related extension requests go through My Tax Account, by email, or by phone at (608) 266-2776.3Wisconsin Department of Revenue. Tax Filing Extensions For Paper and Electronically Submitted Returns
You may file more often than your assigned schedule at any time. Filing less often requires written approval from the department and proof that you’ll have no tax liability in the skipped periods. Annual filers do not file a WT-6 at all; their withholding is reported directly on Form WT-7.1Wisconsin Department of Revenue. Withholding Tax Guide
How to File and Pay
All WT-6 filing is electronic. The department offers five channels:2Wisconsin Department of Revenue. General Withholding Tax Questions
- My Tax Account (MTA). Log in at tap.revenue.wi.gov/mta, select your withholding tax account, choose “File WT-6 Return” for the correct period, enter your withholding total, and submit payment in the same session.4Wisconsin Department of Revenue. How to…
- TeleFile. File by phone at (608) 261-5340 or (414) 227-3895.
- Third-party payroll software. Many payroll providers submit the WT-6 through approved e-file transmission.
- WT-6 file transmission. Direct XML batch submission for employers filing large volumes.
- ACH credit. You initiate payment from your own bank rather than authorizing a debit.
After you submit through MTA, the portal issues a confirmation number. Save it. That confirmation is your proof of timely filing if a notice later arrives.
What to Have Ready
The form asks for a short list of items, but any error can misroute a payment or generate a notice.
- Your 15-digit Wisconsin tax account number. This is different from your federal EIN.5Wisconsin Department of Revenue. Additional Detail Information of WT-6 Batch Payment Schema
- The reporting period. A monthly filer reporting January wages uses a period ending January 31. Semi-monthly filers have two periods per month, ending the 15th and the last day.
- Total Wisconsin income tax withheld. The gross state withholding from every paycheck issued in the period. Do not net it against federal withholding or other deductions.
- Bank routing and account numbers. Needed if you’re paying by ACH debit in MTA.
MTA will pre-fill some of these fields. Verify the period and account number match what you expect before entering the withholding total.
Zero Returns
If your account is open, you owe a WT-6 for every period even when you paid no wages or withheld nothing. Select the period in MTA, enter zero, and submit.2Wisconsin Department of Revenue. General Withholding Tax Questions Skipping a zero return can produce a delinquency notice and a late filing fee even though no tax was due.
Fixing a WT-6 After You File
The correction depends on which direction the mistake ran:
- Underpayment. File a second WT-6 for the same period covering the shortfall. You do not amend the original.6Wisconsin Department of Revenue. Wisconsin Withholding Tax TeleFile
- Overpayment. Request a refund by email, phone, or mail. No special form is required; identify the period, explain the error, and state the overpaid amount. You can instead ask the department to apply the overpayment to a future period.6Wisconsin Department of Revenue. Wisconsin Withholding Tax TeleFile
Refund requests go to DORWithholdingTax@wisconsin.gov, (608) 266-2776, or Wisconsin Department of Revenue, PO Box 8920, Madison, WI 53708-8920.6Wisconsin Department of Revenue. Wisconsin Withholding Tax TeleFile
What a Late WT-6 Costs
Late filings stack multiple charges on top of the withholding you already owe.
- Late filing fee. $50 per delinquent report. Corporations taxed under Subchapter IV of Chapter 71, and insurance companies taxed under Subchapter VII, pay $150.7Wisconsin State Legislature. Wisconsin Statutes 71.83
- Late filing penalty. 5% of the unpaid withholding for the first month, plus 5% for each additional month or partial month, capped at 25%.7Wisconsin State Legislature. Wisconsin Statutes 71.83
- Delinquent interest. 1.5% per month (18% annually) on unpaid withholding, running from the due date until the department receives payment.8Wisconsin State Legislature. Wisconsin Statutes 71.82
- Incorrect or incomplete report. A 25% penalty on the shortfall if the department determines the withholding was underreported or the correct amount was not deposited.8Wisconsin State Legislature. Wisconsin Statutes 71.82
Year-End Reconciliation Is Separate
The WT-6 handles your periodic deposits only. Every employer also files Form WT-7, the annual reconciliation, which ties all your WT-6 deposits for the year against total withholding reported on employee W-2s and any 1099s showing Wisconsin withholding.
Form WT-7, along with W-2s and applicable 1099s, is due January 31 following the calendar year. For tax year 2025, the due date is February 2, 2026, because January 31 falls on a Saturday.9Wisconsin Department of Revenue. Wisconsin Form WT-7 Instructions A 30-day extension is available for filing W-2s and 1099s on a showing of good cause, but the deadline to furnish copies to employees cannot be extended. Extension requests must be filed before the original due date through My Tax Account, by email to WIWithholding@wisconsin.gov, or by mail to Wisconsin Department of Revenue, Tax Operations Business, PO Box 8902, Madison, WI 53708-8902.10Wisconsin Department of Revenue. Forms W-2 and 1099 Filing by Employers and Others Making Reportable Payments
If You Stop Paying Wages
Ending payroll does not end your filing obligation. As long as your withholding account is open, the department expects a WT-6 for every period, and missed periods generate delinquency notices. Close the account in three steps:11Wisconsin Department of Revenue. Closing a Business
- File your final WT-6 covering withholding through the last date you paid wages.
- File Form WT-7 with W-2s and any 1099s within 30 days of the closure date, not at the usual January 31 deadline.
- Request account closure using the “Request to Close Account” feature in My Tax Account, by email to DORWithholdingTax@wisconsin.gov, or by phone at (608) 266-2776.
You still owe a return for every period the account was active, including any periods between your last payroll and the effective closure date.11Wisconsin Department of Revenue. Closing a Business