Modifies provisions relating to property tax assessments

SB 853 modifies Missouri's property tax assessment process by requiring counties to provide property owners with detailed, timely notices when valuations increase. It mandates that assessors notify owners by June 15th of any valuation change, including projected tax liability for the upcoming year, with specific details like tax rates from each local subdivision, previous rates, and contact information. These notices must be sent via mail or in person to the owner's last known address and include all appeal processes. The bill directly affects residential and commercial property owners in counties not under specific charter government rules, ensuring they receive clear information about potential tax impacts before the annual appeal deadline. The changes apply to all counties except those adopting charter government after 2008, with additional online information requirements for large counties (over 1 million people) starting in 2011.