During World War II, Nazi Germany used prisoners in the Sachenhausen concentration camp to produce very high quality forgeries of the Bank of England’s £5, £10, £20, and £50 notes. These were considered the most perfect counterfeits ever produced during the war, and was almost impossible to distinguish from the real currency.

The idea was to drop the forged banknotes over England from airplanes and thus wreck the British economy - however, the Germans used these notes to pay their spies abroad instead!

In fact, after the war, a German spy Elyesa Bazna, unsuccessfully tried to sue the German government for outstanding pay!

Operation Bernhard [wiki] | Operation Bernhardt £5 Note

You’re looking at the replica of $1,000 banknotes that are so well known that they’re usually referred to by their serial number "8894."

This is one of the most widely reproduced replicas of U.S. notes. These items were most probably issued by the phonograph record company Longines Symphonette Society in Larchmont, N.Y., in 1967.

The LSS replica is of a $1,000 Bank of the United States note originally issued in the mid-1800s. The design on the face or front of the note features an impressive looking building in the center with three portraits at either end of the note.

The record firm apparently had these replicas produced as part of a promotion. The replicas were included in sales brochures that went far and wide. The replica notes were printed on imitation parchment and were treated to give them a "yellowed with age" appearance. The key is they all have the same serial number, 8894.

These replicas don’t have any monetary value but they make interesting conversation starters.

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This happened in 2004: a customer ordered $2 worth of food at a Dairy Queen in Kentucky and paid with a $200 bill (complete with picture of the White House lawn with signs saying "We like broccoli") and got $198 change!

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Superdollar: North Korea’s Almost Perfect Counterfeit. The superdollar is the name given to an almost perfect counterfeit of the US banknote, believed to be produced by North Korea in the late 1980s.

The superdollar notes were so good that even experts were fooled for years:

One defector who spoke to Panorama on the condition of anonymity said he had spent his life making counterfeit US dollars, adding that they were such good quality that they fooled experts.

He said: "The counterfeiting was all done at government level. We had a special plant for doing it.

"When I defected I brought some of these counterfeit notes to South Korea, and I showed them to the experts in the South Korean intelligence agency. They said - these are not fake notes. They’re real."

Link | Superdollar [wiki]

The Portuguese Banknote Crisis was the world’s largest case of counterfeiting.

The complex plot was conceived by Alves dos Reis, a Portuguese criminal while he was jailed for illicit arms dealing and embezzlement during World War I. After his release from prison, Reis presented himself as an agent of the Bank of Portugal (which was essentially a private company at the time) with a mandate to negotiate a loan for the ailing Portuguese colony of Angola in Africa.

Reis and collaborators presented this loan as a secret project of the Bank of Portugal and conned the currency printer Waterlow and Sons Ltd. of London to print Portuguese banknotes, specific for Angola, to the tune of 300 million escudos or £3 million (at 1925 exchange rate).

Reis proceeded to launder the money, created his own banks, invested in stocks and currency markets - and even buying stocks in the Bank of Portugal to gain control of that bank so he could thwart investigations into his scheme!

In 1925, the whole scheme came to a screeching halt when a bank teller found bank notes with duplicated serial numbers. All in all, Reis had managed to launder money equivalent to nearly 1% of Portugal’s annual GDP at the time!

The scandal became public knowledge and sparked political and economic instability in Portugal - the following year, the government was toppled in a military coup.

And Alves dos Reis? He was sentenced to 20 years in prison, served his time, and died penniless afterwards.

Link: The Effects of the 1925 Portugese Bank Note Crisis [pdf], an article by Henry Wigan | Alves dos Reis [wiki]

Emanuel "Jim the Penman" Ninger. Emanuel Ninger is a counterfeiter, who drew by hand, various denominations of US banknotes in the late 1880s.

He worked for weeks at a time on each note, and this was profitable because at the time one of those notes was extremely valuable (about $2000 or $4000 in today’s dollars). He gained a following, as the invariably wealthy people that ended up with these banknotes tended to realise their worth as works of art.

He was apprehended by the United State Secret Service in 1896, after a banknote ended up in a small puddle at a bar. A none-too-amused bartender realised that the ink was staining and the note was not genuine. Ninger served six months, and was forced to pay a restitution of $1 (The rumour that the $1 was one of his own works is more than likely an urban legend). He disappeared and probably did not make more works, though the art community was holding out, hoping for more to be discovered. None ever were.

Link: Emanuel Ninger [wiki]