Paychex, Inc. is an American company that provides human resources, payroll, and employee benefits outsourcing services for small- to medium-sized businesses. Founded in 1971 and headquartered in Rochester, New York, the company has more than 100 offices serving approximately 740,000 payroll clients in the U.S. and Europe. Paychex is ranked 681st on the Fortune 500 list of largest corporations by revenue. Wikipedia