The IRS is looking to return $164.6 million in undelivered refund checks. A total of 111,893 taxpayers are due one or more refund checks that could not be delivered because of mailing address errors. IRS Commissioner Doug Shulman said "We want to make sure taxpayers get the money owed to them.""If you think you are missing a refund, the sooner you update you address information, the quicker you can get your money."

A taxpayer only needs to update his or her address once for the IRS to send out all the checks due. Undelivered refund checks average $1,471 this year, compared to $1,148 last year. Some taxpayers are due more than one check.

The average dollar amount for refunds rose by just over 28 percent this year, possibly due to recent changes in tax law which introduced new credits or expanded existing credits, such as the Earned Income Tax Credit. If a refund check is returned to the IRS as undelivered, taxpayers can generally update their addresses with the "Where's My Refund?" tool on IRS.gov. The tool also enables taxpayers to check the status of their refunds. A taxpayer must submit his or her Social Security number, filing status and amount of refund shown on their 2009 return. The tool will provide the status of their refund and, in some cases, instructions on how to resolve delivery problems.

With only a small percentage of checks mailed out by the IRS are returned as undelivered, taxpayers can put an end to lost, stolen or undelivered checks by choosing direct deposit when they file either paper or electronic returns. Taxpayers can receive refunds directly into their bank, split a tax refund into two or three financial accounts or even buy a savings bond.

The IRS also recommends that taxpayers file their tax returns electronically, because e-file eliminates the risk of lost paper returns. E-file also reduces errors on tax returns and speeds up refunds. E-file combined with direct deposit is the best option for taxpayers; it's easy, fast and safe.

The public should be aware that the IRS does not contact taxpayers by e-mail to alert them of pending refunds and that such messages are common identity theft scams. The agency urges taxpayers not to release any personal information, reply, open any attachments or click on any links to avoid malicious code that will infect their computers.