According to the Internal Revenue Service, unclaimed income tax refunds totaling almost $1.4 billion may be waiting for an estimated 1.2 million taxpayer individuals who did not file a 2015 Form 1040 federal income tax return.

To collect the money, these taxpayers must file their 2015 tax returns with the IRS no later than this year's tax deadline, Monday, April 15, except for taxpayers in two states of Maine and Massachusetts, who have until April 17. "We’re trying to connect over a million people with their share of $1.4 billion in potentially unclaimed refunds for 2015,” said IRS Commissioner Charles Rettig. “Students, part-time workers and many others may have overlooked filing for 2015. And there’s no penalty for filing a late return if you’re due a refund.” The IRS estimates the midpoint for the potential refunds for 2015 to be $879 — that is, half of the refunds are more than $879 and half are less.

According to IRS, In cases where a federal income tax return was not filed, the law provides most taxpayers with a three-year window of opportunity to claim a tax refund. If they do not file a tax return within three years, the money becomes the property of the U.S. Treasury. For 2015 tax returns, the window closes April 15, 2019, for most taxpayers. The law requires taxpayers to properly address, mail and ensure the tax return is postmarked by that date.