The Internal Revenue Service said it has unclaimed refunds totaling more than $1.3 billion awaiting nearly 1.4 million people who did not file a federal income tax return for 2006, including over $150 million in the state of California alone.

To collect the unclaimed money, taxpayers must file a return for 2006 with the IRS no later than Thursday, April 15, 2010. The IRS estimates that the median unclaimed refund for tax-year 2006 is $604.

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 the refund within three years, the money becomes the property of the U.S. Treasury.

By failing to file a return, people stand to lose more than refunds of taxes withheld or paid during 2006. For example, most telephone customers, including most cell phone users, qualify for the one-time telephone excise tax refund. Available only on the 2006 return, this special payment applies to long-distance excise taxes paid on phone service billed from March 2003 through July 2006. The government offers a standard refund amount of $30 to $60, or taxpayers can base their refund request on the actual amount of tax paid. For details, see the Telephone Excise Tax Refund page on IRS.gov.

In addition, many low-and-moderate income workers may not have claimed the Earned Income Tax Credit. The EITC helps individuals and families whose incomes are below certain thresholds, which in 2006 were $38,348 for those with two or more children, $34,001 for people with one child and $14,120 for those with no children. For more information, visit the EITC Home Page.