The IRS has announced that there is $1.1 billion in previously  unclaimed tax refunds waiting for nearly 1.1 million people who did not file a federal income tax return for 2007. According to Walletpop.com, the IRS estimates that half of these potential 2007 refunds amount to at least $640.

To get your money, you have to make the first move. The IRS won't send you a tax refund if you haven't filed a federal income tax return. Many taxpayers may not realize that they might qualify for a refund because they erroneously believe that they did not make enough money. However, some taxpayers may be eligible for refundable credits.

A popular -- but still underutilized -- refundable credit is the Earned Income Tax Credit (EITC). The EITC helps individuals and families whose incomes are below certain thresholds, which in 2007 were $39,783 for those with two or more children, $35,241 for people with one child, and $14,590 for those with no children.

Other credits may also apply, such as the Making Work Pay Credit. The Making Work Pay Credit offers a flat credit of up to $400 for individual taxpayers and up to $800 for taxpayers who are married but filing jointly.

Refunds may also be due to taxpayers who might have too much withholding. This can happen when taxpayers claim too few exemptions on their form W-9. Form W-9 can be particularly confusing for taxpayers with more than one job or for married couples who both work.

If you're not sure whether you would be eligible for a refund, consider filing a return. If it turns out that you're due a refund, there's no penalty for filing late. Of course, remember that your 2007 refund will be held if you have not filed federal income tax returns for 2008 and 2009. Your refund may also be held if you're subject to offset for unpaid taxes, child support or federal debts.

The last day to file and receive a refund for 2007 is April 18, 2011. After that date, any unclaimed money will be returned to Uncle Sam.

More From The New 96.1 WTSS