Last year the IRS reported 95,746 refund checks totaling $92 million (an average of around $963 per taxpayer) were returned by the post office as undeliverable, due to unreported changes of name and/or address.

It's important to realize undeliverable refunds are but one small component of unclaimed assets held by the IRS. A significantly greater number of checks are delivered, but for one reason or another remain uncashed. Estimates are the total amount is in excess of $8 billion.

If a check is returned by the post office as undeliverable, IRS will attempt to obtain a correct address for the taxpayer. If successful, the check is reissued. If no new address is available, the check is returned to the U.S. Treasury. IRS policy is to credit any amount due to returns filed during the succeeding three years. But if no returns are filed, the account reverts to inactive status and is removed from the active master file.

Regarding delivered but uncashed checks, unless the taxpayer contacts the IRS, they have no way of knowing the check was not cashed. All Treasury checks now expire one year from the date of issue; so if you discover an uncashed check more than a year old, you will have to apply for a replacement.

IRS Code specifically prohibits any tax refund from escheating to individual states, so a check of your local unclaimed property office will not provide any useful information. For assistance tracing and claiming IRS income tax refunds go to: IRS Refund Search