Wis. Stat. § 70.52: Clerks to examine and correct rolls.

Each city, village, and town clerk upon receipt of the assessment roll shall carefully examine the roll. The clerk shall correct all double assessments, imperfect descriptions, and other errors apparent on the roll, and correct the value of parcels of real property not liable to taxation. The clerk shall add to the roll any parcel of real property not listed on the assessment roll and immediately notify the assessors of the additions and omissions. The assessors shall immediately view and value the omitted property and certify the valuation to the clerk. The clerk shall enter the valuation and property classification on the roll, and the valuation shall be final. To enable the clerk to properly correct defective descriptions, the clerk may request aid, when necessary, from the county surveyor, whose fees for the services rendered shall be paid by the city, village, or town.