Download this free comprehensive Independent Contractor Agreement template that includes the main clauses and best practices to protect your company. An independent contractor agreement is a contract between a freelancer and a client outlining work specifics.SUBSTITUTE FORM W-9 REQUEST FOR TAXPAYER IDENTIFICATION. With an employee, rather than an independent contractor, an employer withholds income tax, Social Security tax, and Medicare tax from their wages. In addition to employees, independent contractors often sign certain types of nonsolicits. Invoice substantiating payment amount. I hire or contract with individuals to provide services to my business. Medical Van Couriers Independent Contractor-Salt Lake City.