Property Tax Basics
Two separate offices handle property taxes here
Matagorda County has two separate offices for property taxes — one sets values, and one collects the bills.
The Matagorda County Appraisal District sets the value of your property. It is on Avenue G in Bay City. This is where you file for a homestead exemption or protest your appraised value. The appraisal district does not collect money.
The Tax Assessor-Collector is a separate office on 7th Street in Bay City. That office sends the tax bills and takes payments. It also handles vehicle registration. If you get a bill that looks wrong, start with the appraisal district — not the collector.
Source to confirm: Texas Comptroller — Matagorda County Directory