IRS May Retain $1 Billion in Taxpayer Refunds – File now to receive your refund The IRS is going to keep close to one billion dollars in unclaimed refunds from those who have not filed a 2012 tax return. Do not let this happen to you or someone you know. The IRS estimates that one million taxpayers may lose close to $1 billion in refunds if they do not file their 2012 tax return before the upcoming April filing deadline. Don’t let this happen to you or someone you know. Here is what you need to know. The three-year rule.