Harris County Tax Office Forms. Automotive Property Tax Special Permit Taxes VoterRegistration Miscellaneous.Which forms will I need to file? For Harris County Appraisal District, most businesses will need to file the general rendition form, 22.15. How do I fill this out? The forms listed below are PDF files. They include graphics, fillable form fields, scripts and functionality that work best with the free Adobe Reader. Online Forms, Applications, and Database Searches. The Real Property Department records documents pertaining to real property or real estate in Harris County. Nontangibles such as goodwill, accounts receivable, and propriatary processes are not taxable for county appraisal district purposes.