Understand tax requirements when hiring a foreign contractor. Our guide provides essential insights for seamless compliance with international tax laws.The transition includes the transfer of all records, and other data in the possession, custody, or control of contractor required to be provided to the County. Create an international contractor agreement that defines the fees, payment terms, and scope of work. Onboard the contractor and begin work. 1. After Contract Award the Contractor shall complete the Vendor Registration. Form located on the County Department of Finance Vendor Registration Web Site. This is a written agreement under the compulsory Workers' Compensation laws of the State of Arizona, A.R.S. § 23-901 (et. Seq.), and specifically A.R.S. Going to hire a contractor in the USA?