I'd come home from a nights shenanigans with half a $20 bill in my pocket. How I'd torn it, nor where the other half was were both a faded memory. Luckily, the half I held was slightly larger than 50% of the bill, so I knew I could get a refund.
About.com has some pretty detailed notes about how to send in your damaged currency, As does FEMA, but the real government reference is the Bureau of Engraving, their page about damaged currency, or their simple how to submit a claim explains it all.
It's recommend you send all claims by “Registered Mail, Return Receipt Requested”, but that just costs more, and for my measly $20, I was looking to cut my losses. I simply included a nice letter with my currency and sent it to the government agency responsible for replacing mutilated currency, their address is below:
Department of the Treasury
Bureau of Engraving and Printing
Office of Currency Standards
P. O. Box 37048 Washington, D. C. 20013
Sure enough, many moons later, I was greeted with a strange check in the mail, pictured below:
After cracking the envelope open, I noted the exact amount, and the tiny note in the bottom: Mut. Curr Refund My $20 bill had been resurrected as a government check!
It took 6 months to get the refund. Six months. It was so long ago, I had to check the photo's date of the top photo to remember when I sent it - October 1, 2010, and I got the check in early April, 2011. But hey, drinks on me tonight!