According to state law, your tax obligation is established on January 1. Even if you move out-of-state the next day, you are still obligated to pay Missouri taxes. State law makes no provisions for pro-rating your personal property tax bill. If you move out of Buchanan County, please contact the Assessor's office (816-271-1520) with your new address. If moving to another county in Missouri, you will also need to notify your new Assessor's office of your new residence.