Jefferson County Residents: File Personal Property Tax by May 1 | The Locally Times

Failure to file reminder assessment lists by the May 1 deadline will result in late penalties, according to county records.

Jefferson County residents who have not yet filed their personal property assessment lists must do so by May 1, 2026, to avoid late penalties. The Jefferson County Assessor's Office mailed initial assessment lists in early January 2026. For those who did not return their original forms, the Assessor's Office began sending out "Reminder" forms later in March. Taxpayers can also choose to e-file their 2026 Assessment List. The reminder forms will include a link to the e-file website, along with an account number and PIN. Residents who have not received a 2026 assessment list by the end of March are advised to contact the Assessor's Office directly. Per Missouri State Statutes, these reminder assessment lists must be e-filed or returned to the Assessor's office before the May 1 deadline. The Assessor's Office can be reached at 636-797-5343 or ppassessor@jeffcomo.org.