General Information - Software Developer Specifications for WT-6

​​​​​Filing and Paying Timely

The due dates for Withholding Tax Deposit Reports depend upon the Employer's assigned filing frequency. If a due date falls on a weekend or state holiday, the due date is extended to the next regular business day. Transmissions must be received by the due date and should be transmitted prior to the 11:00 PM CT cut-off on the due date.

If paying by EFT, the EFT payment must settle in the state account on or before the due date in order to be considered timely. The EFT debit payment included in the file transmission must be initiated by 3:00 PM CT on the banking business day prior to the requested settlement date/due date.

Note: Due dates for filing are extended based on state business days, while due dates for EFT payments are based on Federal Reserve/banking business days. These two schedules are not always the same.

Data Requirements

Zero or Blank Fields - You do not need to transmit any optional element that has a zero or is blank. Send data elements only if they contain data values. Do not send empty data elements (i.e., zero financial fields, unused elements, etc.).

Payment Methods

Employers filing electronically must make payments electronically either by including Electronic Funds Transfer (EFT) information in the electronic return or independent of the file transmission process. The following options are available:

Note: You may not pay by paper check in the Withholding Tax Deposit Report e-File process. Registrants should not submit a check to WDOR. If a check is mailed, WDOR cannot guarantee proper or timely processing of the paper check.

Changes to Returns Electronically Filed, Amended Returns

A return cannot be recalled or intercepted once it has been transmitted. Any changes to entries after a return has been transmitted must be retransmitted as an amended return. There is an AmendedReturnIndicator in the ReturnHeaderState to identify the return as amended.

Note: Do not include redundant EFT payment information with the amended transmission. All EFT payments with amended transmissions will be processed. You may include an additional payment if the amended return resulted in an additional amount due.

Rejected Returns - Perfection Period

The reject notice will contain information about the errors. Rejected returns are not considered filed. The transmission should be corrected and resubmitted. Only an accepted transmission is considered filed and will be issued a confirmation number. If a timely submitted return is rejected, but corrected, resubmitted and accepted within 10 calendar days, the resubmitted return will be considered timely. Use the OriginalSubmissionId and OriginalSubmissionDate elements in the ReturnHeaderState to tell our system that this is a resubmission of a perfected return.

DOR Adjustments

WDOR reserves the right to review the transmission, including late filing fee, interest, and penalty reported in the transmission. This review may result in a Notice of Amount Due or Refund. In these cases, WDOR will issue a Notice of Adjustment with a tear off payment voucher. This notice is mailed directly to the withholding tax registrant. If the withholding tax registrant agrees with the notice, the amount due should be mailed with the tear off payment voucher to the address on the voucher. Appeal rights and procedures are explained on the back of the Notice of Adjustment and should be followed when the withholding tax registrant does not agree with the adjustment.

Participation in the e-File Program

The Wisconsin Withholding e-File program is open to all employers with a Wisconsin Tax Number; there is no separate registration requirement for either filing or paying electronically. We also welcome any/all payroll service providers or other practitioners who file or pay on behalf or employer clients. All employers are now required to file electronically using one of the approved methods, and most are required to pay electronically.

Withholding Tax e-File Developer eMailing lists

The dor-withefiledev listserv is designed to provide electronic communication of interest to developers of withholding tax e-File applications. Information on how to subscribe (or unsubscribe) is found on our website at Subscribe to E-filing News ​- Withholding Tax e-File Developer.

Please email DORDeveloperRelations@wisconsin.gov for further information. List XML Withholding WT-6 in the subject line.

October 10, 2023​