BOSTON -- The Internal Revenue Service is looking thousands for taxpayers who are missing economic stimulus checks and refund checks after the checks were returned by the U.S. Postal Service due to mailing address errors.

"People across the country are missing tax refunds and stimulus checks. We want to get this money into the hands of taxpayers where it belongs,” said IRS Commissioner Doug Shulman. “We are committed to making the process as easy as possible for taxpayers to update their addresses with the IRS and get their checks."

More than 279,000 economic stimulus checks totaling about $163 million and more than 104,000 regular refund checks totaling about $103 million were sent back to the IRS.

All a taxpayer has to do is update his or her address, and the IRS will then send out all checks due.

The IRS urged taxpayers who may be due a stimulus check to update their addresses by Nov. 28, 2008. By law, economic stimulus checks must be sent out by Dec. 31. The undeliverable economic stimulus checks average $583.

The Where’s My Stimulus Payment? tool is the quickest and easiest way for a taxpayer to check the status of a stimulus check and receive instructions on how to update his or her address. Taxpayers without Internet access should call 1-866-234-2942.

The regular refund checks that were returned to the IRS average $988 and will be resent as soon as taxpayers update their address. Taxpayers can update their addresses with the Where’s My Refund? tool. Taxpayers checking on a refund over the phone will be given instructions on how to update their addresses by calling 800-829-1954.