Transaction date of Harris County Tax Office online payment portal; transaction date of telephone payment. Q. Where can I pay my property taxes?This publication explains how you can recover the cost of business or income-producing property through deductions for depreciation. The general deadline for filing an exemption application is before May 1. The County Clerk's Office records and maintains the records of the Commissioners Court, the Probate Courts, and the County Civil Courts at Law. All property is taxable unless federal or state law exempts it from the tax. Step 1: Completing the Protest Form. Which forms will I need to file? For Harris County Appraisal District, most businesses will need to file the general rendition form, 22.15. If taxpayer name or address has changed or is incorrect, provide correct name and address in the space provided. 2.