BIRMINGHAM — Refunds totaling more than $1.1 billion may be waiting for nearly 1.1 million people nationwide who did not file a federal income tax return for 2007, the Internal Revenue Service announced today.

In Alabama alone, $15,649,000 in refunds may be waiting for 17,600 people.

To collect the money, a return for 2007 must be filed with the IRS no later than Monday, April 18, 2011.

The IRS estimates that half of these potential 2007 refunds are $640 or more. In Alabama, half of the refunds are $634 or more.

Some people may not have filed because they had too little income to require filing a tax return even though they had taxes withheld from their wages or made quarterly estimated payments. In cases where a return was not filed, the law provides most taxpayers with a three-year window of opportunity for claiming a refund. If no return is filed to claim a refund within three years, the money becomes property of the U.S. Treasury.

For 2007 returns, the window closes on April 18, 2011. The law requires that the return be properly addressed, mailed and postmarked by that date. There is no penalty for filing a late return qualifying for a refund.