10. Citibank overpays by $892 million

TonyTheTiger / English Wikipedia

This mortifying financial error was recently incurred by New York-based Citibank.

Three employees accidentally processed an interest payment that transferred a whopping $900 million to Revlon lenders, reported Bloomberg in 2020. They were supposed to send $8 million.

The bank has managed to recover $390 million so far.

The Financial Post reported in February that a federal judge in Manhattan ruled Citibank is not entitled to recoup the remaining $510 million. The company is appealing the ruling.

9. Samsung Securities spills shares worth $105 billion

Samsung headquarters
Oskar Alexanderson / Flickr

An employee at Samsung Securities, a South Korean financial branch under the larger Samsung umbrella, doled out almost three billion shares into employee accounts in 2018 — more than 30 times the number of Samsung’s existing shares.

The employee was supposed to pay out 1,000 won ($0.92 U.S.) per share in dividends, but confused won for shares, explains The Wall Street Journal.

While the company blocked employees from selling their newly acquired shares 37 minutes later, the damage had already been done. Several staff members sold close to $187 million worth of shares within the half hour.

8. Alitalia prices tickets to Cyprus for $33 each

RussellHarryLee / Flickr

In 2006, an employee at Italian airline Alitalia forgot to input the two extra zeros when pricing business-class tickets from Toronto to Cyprus.

A business-class ticket from Toronto to Cyprus would have cost $2,558, according to the Wall Street Journal. Due to the exchange rate on that day and the clerical error, hundreds of buyers managed to snag fares for just $33.

The airline did the right thing and chose to honor the heavily discounted price for the 509 people who bought tickets before the error was detected, reports CBC News.

7. Whopper of a discount at Burger King costs $8.2 million

Burger King
Anthony92931/ Wikimedia Commons

Everyone loves a good two-for-one burger deal. But a discount gone wrong cost this franchisee millions.

In 2019, Burger King franchisee Carrols Restaurant Group offered “two Whopper Jr. sandwiches for $4, two Whoppers for $5 and two Double Whoppers for $6,” according to the Syracuse Post-Standard. Customers were supposed to be charged full-value on fries and drinks on their orders but were charged discounted prices on those as well.

The bungle cost restaurants about $1.50 on each sale — adding up to $8.2 million overall.

6. Zappos sister site loses $1.6 million in fire sale

E-commerce online shopping concept. Miniature of reusable grocery bags.
Creative Caliph / Shutterstock

Discount clothing site 6pm once capped every item in the store at $49.95, according to a 2010 article by Fast Company.

The retailer carries a number of luxury brands that “can reach into the thousands of dollars,” so plenty of bargain hunters managed to snag some ridiculously good deals.

6pm ended up honoring the sales, which occurred within a six-hour time frame, costing parent company Zappos (owned by Amazon) over $1.6 million.

5. Uber owes drivers $45 million due to accounting mistake

Stock Catalog / Flickr

Uber has been in the news for its strained relationship with drivers for years. But, in 2017, the ride-sharer admitted it made an embarrassing accounting error by overcalculating its commission cut.

The error went all the way back to 2014 and was estimated to cost the company up to $45 million in refunds, including interest.

The ride-sharing company told Quartz that it would refund the affected “tens of thousands” of drivers around $900 each.

4. Mizuho Securities trader tries to sell 610,000 shares at 1 yen apiece

The Tokyo Stock Exchange.
Lombroso/Wikimedia Commons

In 2005, a trader from Japanese firm Mizuho Securities was trying to sell a single share of J-Com Co. for 610,000 yen ($5,888 U.S.).

A typing error caused him to sell 610,000 shares at 1 yen apiece instead — 41 times the number of existing shares.

Fox News alleges another trader tried to cancel the order, but since the Tokyo Stock Exchange (TSE) doesn’t cancel orders, the error ended up costing Mizuho Securities $335 million.

TSE president Takuo Tsurushima resigned shortly after the debacle, admitting that the exchange was partly to blame, and Mizuho Securities attempted to sue for over 40 billion yen.

3. Spreadsheet error costs JPMorgan $3.1 billion

Top of JPMorgan Chase Tower, Dallas, Texas.
Joe Mabel/Wikimedia Commons

You might recall the “London Whale” incident in 2012, when notorious trader Bruno Iksil — whose other monikers include the White Whale and even Voldemort — conducted a series of credit default swaps that cost JPMorgan Chase $6.2 billion.

What you might not know, however, is that half the loss was incurred by a simple Excel spreadsheet error.

Bloomberg reports that the Excel model, which relied heavily on copy and pasting of information, accidentally “underestimated risk by half.”

As for Iksil himself? He was fired shortly after the incident but may have reached an agreement with federal authorities to avoid criminal prosecution, The Wall Street Journal reported in 2013.

2. Google trainee makes $10-million dummy advert

The Google homepage on a phone.
Solen Feyissa/Flickr

Ever experienced a rough first week on the job? It probably wasn’t this bad.

In 2018, an employee at Google pressed the wrong key during a training exercise and put up a blank yellow rectangle on a "huge number" of sites across the U.S. and Australia for around 45 minutes, reported the Financial Times.

The trainee allegedly placed orders at “as much as 10 times the normal market price for the adverts,” costing the tech giant an estimated $10 million.

1. Missing comma costs Lockheed Martin $70 million

Lockheed Martin
Lockheed Martin

Lockheed Martin issued a contract to a customer with a missing comma — in the sale price.

The customer held the aerospace company to the offer, costing Lockheed Martin $70 million for a C-130J Hercules aircraft in June 1999.

This wasn’t the only expensive mishap of that year. A few months later, a simple math conversion error involving both Lockheed Martin and NASA resulted in the loss of a $125 million Mars probe. Yikes.

About the Author

Serah Louis

Serah Louis

Staff Writer

Serah Louis is a staff writer with MoneyWise.com. She has a Bachelor of Science from the University of Toronto, where she double majored in Biology and Professional Writing and Communications.

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