A refund claim is generally made by filing an original or amended tax return. The refund claim must be filed within 3 years of the due date of the original return. The due date is usually April 15th, but the IRS has extended the due date in several years in response to disasters. Check the due date for that tax year to be sure. If the client is eligible for the Earned Income Credit, an original or amended tax return should be filed immediately for each of the last 3 years. If you are close to the 3-year time limit, be sure to get a proof of postmark or mailing or hand deliver the returns to an IRS office and get a receipt for the refund claims. The denial of a refund claim may be appealed to an IRS appeals officer.