Since the government gives companies and employees tax breaks for sponsoring and contributing to retirement plans, it wants to know that those breaks are being distributed fairly across all levels of pay. (inc.com)
Employee tax records — Keep at least four years after the date the tax becomes due or is paid, whichever is later. (realtormag.realtor.org)
This applies to software that has full payroll abilities, including the ability to automatically calculate employee taxes, print checks, or pay by direct deposit. (lawyerist.com)