Complete section 1 on the front of the form to identify any changes to the business name, mailing address, or location address. Is my inventory taxable?Your business must register with ADOR before conducting any taxable business activity in Arizona for transaction privilege tax (TPT) and withholding purposes. All bids for goods and services currently being solicited are posted on the Office of Procurement Services' web site at the URL shown above. A region code is a two-letter code (e.g. Visit your Student Center through maricopa. All Maricopa County residents aged 65 or older are eligible, but only for courses having seats available as of the second day of class. Qualify for Discounts. Business Transition. Find local businesses catering to animal needs on Maricopa's Business Registry.