The e-RETR is an electronic way for people to file their transfer return straight to the Wisconsin Department of Revenue. Filing electronically became mandatory on July 1, 2009. It is easy to do and as soon as the electronically filed RETR is recorded by the county register of deeds, the data is immediately available to county officials, assessors, and the Wisconsin Department of Revenue. For more information on how to access the eRETR click the link below.