If you've got any dollar bills on you, then it might be worth pulling them out and scanning ID numbers as some are fetching for as much as $150,000.
Usually when you hear of news that there's low-value currency going for thousands it means there's only a few thousand bills, but for this particular mistake, there are millions of $1 notes in circulation.
So, it might be time to crack open your wallet to see if you have any tucked away - after all, surprise money is the best.
The federal printing error
Back in November 2014, the US Bureau of Engraving and Printing ordered a batch of single dollars to be printed out of a factory in Washington D.C - and everything with the process went smoothly, actually.
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The c**k-up actually came just under two years later in July 2016, when the agency sent the exact same request to a facility in Fort Worth, Texas, according to The Wealthy Nickel.
This meant the bills didn't each have a unique serial code to identify them with - and US Bureau of Engraving and Printing seemingly didn't catch it.
NBC Los Angeles reported that one batch was issued in New York, while the other was in Washington D.C, so they really could be anywhere.
What to look out for
To identify them you'll need to look carefully for three minor things on the misprinted notes.
The Wealthy Nickel says the first of which is whether it has a 'B' Federal Reserve Seal inscribed on it above the serial number - if it doesn't have this then you can stop looking.
Next, look at the series date which is located close to the picture of the Founding Father George Washington, it should read 'Series 2013' - again, if it doesn't go check another bill.
Finally, if the note has both of the above, then what your looking for is a serial number that ends with an asterisk and falls between B00000001* and B00250000*, or B03200001*-B09600000*.
Chances of owning one of the misprints
Well, going off the serial numbers, there's 6.4 million of these suckers out there with approximately 14,500,000,000 one dollar bills in circulation, as of the end of 2023 - according to the Board of Governors of the Federal Reserve System.
I'm no mathematician but I believe the face-value chances of owning one of those notes is 0.04 per cent chance - and that's without factoring in there being an estimated 334,900,000 people living in the US.
In terms of any being found, nine have since been located.
However, unfortunately you'd have to locate it's matching pair to be able to be able to cash in it's true value - although I'm sure you could fetch a pretty penny if you flogged one on its own on eBay,
Estimated valuation
If you are lucky enough to have one, experts believe they could fetch between $20,000 and $150,000 from currency collectors - depending on the condition they are in and their serial number.
Chad Hawk, vice president of PMG, a paper grading company, told Fox Business that the 'last pairing I think I saw sold for about $6,000'.
As for why they are so sought after? Well, according to The American Numismatic Association (via NBC Los Angeles), misprints are very rare - therefore making them a valuable collection piece.
Joe Yates