Most expensive error note

The most expensive error banknote is the "Del Monte Note", a $20 bill that sold for $396,000 (£312,749) at Heritage Auctions (USA) on 22 January 2021. The note acquired its unique name after a Del Monte fruit sticker got stuck to it during the printing process.

Error banknotes are, as the name would suggest, banknotes that made it into circulation with printing errors of some kind. The Del Monte note is an extremely rare type of error note called a "retained obstruction" in which a foreign object (in this case the sticker from a Del Monte-brand banana) is affixed to the paper during the printing process, and then remains attached to the note after it has entered circulation.

The Del Monte Note was printed at the Bureau of Engraving and Printing facility in Fort Worth, Texas. Bills printed here go through three stages of printing, and it seems that the Del Monte sticker was placed on the note between the second and third stage of the process, indicated by the fact that it sits over part of the word "Twenty" but under the serial number and US Treasury seal. Experts believe the sticker was likely placed deliberately by a bored employee.

The note was found by a college student in Ohio, who got it from an ATM in 2003. He sold it on eBay for $10,000 and it has been resold several times since then.