LA CROSSE, Wis. (WKBT) -

Mail-in absentee voting is underway in Wisconsin, but officials are seeing mistakes on many voters' ballots.

Absentee voters are required to have a witness present when they fill out and submit the forms. And new changes to absentee voting require an address for the voter's witness, but people are consistently missing the information on their forms.

La Crosse's City Clerk says she's seeing two absentee ballots a day that are incomplete because of the missing address. Officials will often call a voter if the address is missing, but other mistakes are not as easy to fix.

"If it doesn't get corrected, then that is a reason for the ballot to be rejected. So, it's important that voters read the information, the instructions that are included in the absentee ballot envelope,” said La Crosse City Clerk Teri Lehrke.

Another change in the absentee voter law says the ballot must be received by the city clerk on or before Election Day. Previously, absentee ballots only needed to be post marked by Election Day and received by that Friday.

Officials say any absentee ballot mistake can be fixed by contacting the city clerk.