In November 2009, DOR notified all registered employers in the Withholding Tax Update that they should use their 15-digit Wisconsin tax account number on all withholding correspondence including W-2s, WT-6s, WT-7s, W-2Gs, 1099-Rs and 1099-Ms. For withholding, this number begins with 036. DOR software vendor specifications do require an entry field of 15-digits. Please contact your software vendor if the vendor does not provide a field large enough to accept 15 digits. If the employer has already prepared their W-2s with the short number, you may tell them we will accept them this year. However, going forward, they must use the 15-digit number.

January 14, 2010