DENVER -- The Internal Revenue Service said Wednesday that 2,312 Colorado taxpayers are due refund checks worth more than $2 million dollars that haven't been claimed.

The refund checks, for a total of $2,211,097, were returned as undeliverable and averaged about $956 per check.

According to the IRS, some lucky taxpayers have more than one check waiting.

To see the refund list in a pdf format click here.

Refund checks are mailed to a taxpayer's address on his/her tax return. A refund check is normally returned as undeliverable when a taxpayer moves without updating their address with either the U.S. Postal Service or the IRS.

"It’s hard to believe this many taxpayers don't miss their tax refunds, but it happens year after year," said IRS spokesperson for Colorado, Jean Carl. "There are several ways for taxpayers to update their addresses and claim their refunds."

The "Where’s My Refund?" tool on IRS.gov enables taxpayers to check the status of their refunds. A taxpayer must submit their social security number, filing status and amount of refund shown on their 2006 return. The tool will provide the status of their refund and in some cases provide instructions on how to resolve delivery problems.

Taxpayers can also update their addresses, using the same tool.

A telephone version of the tool is available by calling 800-829-1954.

Taxpayers can access a telephone version of “Where’s My Refund?” by calling 1-800-829-1954.

The IRS suggests direct deposit of refunds to avoid having refund checks delivered to an old address. Taxpayers can sign up for direct deposit on their tax form.