The Internal Revenue Service has almost $1.3 billion in unclaimed 2005 tax refund money that is due to missing filers in each state, as well as in U.S. territories and to members of the military stationed worldwide.

Within U.S. borders, California has the most nonfiling residents -- 154,500 -- for the 2005 tax year. But within the country's contiguous borders, errant New Hampshire filers are likely to get more money. The IRS says the median check in the Granite State comes to $667, meaning half of the taxpayers there can expect to get at least that much when they do file.

Military taxpayers are the biggest potential refund recipients of all. Half of the members of the armed forces who didn't file 2005 returns could collect checks of around $800 by getting in their old forms by the coming April filing deadline.

State by state

If you're one of these nonfilers, you've got until April 15 to send in your 2005 return or you'll forfeit your refund. You can call the IRS' toll-free help line at (800) 829-1040 for assistance if you have additional questions about these undistributed refunds.

Freelance writer Kay Bell writes Bankrate's tax stories from her Austin, Texas, home. She also writes two tax blogs, Eye on the IRS for Bankrate and Don't Mess With Taxes, and is the author of the book "The Truth About Paying Fewer Taxes."