The Internal Revenue Service said it has more than $674,000 worth of refund checks owed to Hawai'i residents that have been returned as undeliverable.

The checks for 682 residents have an average refund of $989 and can be claimed as soon as the owners update addresses with the IRS.

The tax agency said people who think they are owed checks can use the "Where's My Refund" feature on the www.IRS.gov Web site to get the status of their refunds. They can also call (800) 829-1954.

Taxpayers can update their address on the Web site and will receive instructions on other steps to take if they are calling by phone.