The vending machine swallowed half of my $5 bill, and the other half remained in my hand. Can I get my $5 back, or is it all lost forever?
According to the U.S. Bureau of Engraving and Printing, if you have clearly more than one-half of the current bill remaining, you should be able to take it to your bank and exchange it. But if for some reason your bank will not take it, you can submit it to Bureau of Engraving and Printing Office of Currency Standards.
Question asked on https://www.moneyfactory.gov/resources/faqs.html
I have some currency that was damaged. My bank will not exchange it for undamaged currency. What can I do? The Bureau of Engraving and Printing's Office of Currency Standards processes all requests for reimbursement for damaged United States currency. They decide the redemption value of torn or otherwise unfit currency by measuring the portions of the notes submitted. Generally, they reimburse the full face value if clearly more than one-half of the original note remains. Currency fragments measuring less than one-half are not redeemable. Go to the Damaged Money section of our website for additional information and the procedures to redeem mutilated currency.
However take notice of this:
Any badly soiled, dirty, defaced, disintegrated, limp, torn, worn, out currency note that is CLEARLY MORE than one-half of the original note, and does not require special examination to determine its value. These notes should be exchanged through your local bank.