Mon - Fri 7am - 7pm cash, all credit cards, check McLan Accounting Services LLC's payroll services can help you reduce the time spent on administration through developing and implementing a computerized payroll system that will facilitate processing, timely payment and preparation of tax returns. April 15 has come and gone and another year of tax forms and shoeboxes full of receipts is behind us. But what should be done with those documents after your check or refund request is in the mail? Federal law requires you to maintain copies of your tax returns and supporting documents for three years. This is called the "three-year law" and leads many people to believe they're safe provided they retain their documents for this period of time. However, if the IRS believes you have significantly underreported your income (by 25 percent or more), it may go back six years in an audit. If there is any indication of fraud, or you do not file a return, no period of limitation exists.To be safe, use the following guidelines.