1. Articles
  2. Ten Memorable Excel Disasters

An office worker reacts with horror at something he sees on his computer screen.

Pretty much anyone who has ever used Excel has a horror story or two to share—a misplaced decimal, a missing minus sign, a botched cut-and-paste, or some other minor blunder with potentially major consequences. If we’re lucky, we catch the mistakes ourselves. Sometimes, we can repair the resulting damage reasonably quickly and painlessly.

Sometimes, though, an innocent spreadsheet error can wreak havoc. It can cost a company millions, or even put lives at risk. In an earlier article, we mentioned five famous spreadsheet fiascos. Those five cases, while memorable, represent the mere tip of the iceberg. The internet abounds with cautionary tales that could keep any Excel user awake at night.

So, here are ten more of the world’s most memorable Excel disasters.

1. Public Health England misplaces nearly 16,000 COVID-19 positive tests

Here’s an Excel tidbit that will likely never impact your work. An Excel spreadsheet has a physical limit of precisely 1,048,576 rows.

conceptual UK Flag with covid virus overlayed

Chances are, that’s more than enough to handle your company’s monthly sales report (if not, can we come and work for you?). But, the limitation proved disastrous in the U.K. during the pandemic. Public Health England, the agency responsible for aggregating and publishing COVID-19 data, imported a massive CSV file from a private lab—and exceeded Excel’s size limit. As a result, thousands of records at the end of the file failed to import. Nearly 16,000 cases therefore went unreported, and as many as 50,000 potentially infected people were never warned to self-isolate.

2. AstraZeneca includes confidential company information in a massive mailout

These days, UK pharma giant AstraZeneca is best known as the corporate partner in the Oxford vaccine for COVID-19. Back in January 2012, however, the company’s press coverage was much less flattering.

photograph of hand pointing at excel sheet with a pen

At the end of 2011, AstraZeneca sent its financial forecasts to a large list of analysts that subscribe to the company’s corporate updates. In creating the spreadsheet, however, some hapless employee used an Excel template embedded with confidential company information. In other words, highly sensitive corporate secrets were publicly exposed in a mass email.
It was a devastating blunder at the tail end of a difficult year for AstraZeneca. Luckily, thanks to the Oxford vaccine, their 2021 prospects are infinitely brighter.

3. Fannie Mae $1 billion+ error

In 2003, U.S. home mortgage company Fannie Mae updated its accounting standards. In doing so, it processed its internal, automated data using spreadsheets that incorporated some additional calculations.

spreadsheet on laptop screen, with large error message

Unfortunately, one of those spreadsheets also incorporated a small but consequential error. By the time the company caught the error, it had already released financial results that in some cases were more than $1 billion out of whack.

4. University of Toledo’s $2.4 million mistake in projected revenue

2004 was already a tough year for the University of Toledo. The state of Ohio had already hit the institution with significant funding cuts.

man and woman teacher in classroom, both with hands in their hair with frustration

Then, things got worse. The university was projected to lose ten percent of its enrollment, but an employee made a mistake in a spreadsheet formula that instead showed an increase. Relying on that spreadsheet, officials overestimated tuition revenue by a whopping $2.4 million.

There is one bright side to the story, however. The university’s president said that the employee in question had an otherwise unblemished performance record, and that no job action would be taken.

5. RedEnvelope loses more than a quarter in share value thanks to budgeting error

Ecommerce site RedEnvelope saw its share value plummet by more than a quarter in a single day. Because of a spreadsheet error, the company had wildly overestimated its gross profit margins. They were instead forced to go public with a predicted loss for the quarter between $3 million and $3.5 million.

photograph of man in an office carrying belongings in cardboard box

While the University of Toledo employee kept their job, the fallout at RedEnvelope was considerably messier. Its chief financial officer felt compelled to resign.

6. Eastman Kodak’s $11 million severance error

In 2005, a faulty spreadsheet caused Kodak’s severance pay figures to be off by $11 million. Amazingly, the error affected just a single employee. In a nice bit of corporate understatement, Kodak’s CFO attributed the error to “an internal control deficiency that constitutes a material weakness that impacted the accounting for restructurings.”

At the time, Kodak was losing over $1 billion per quarter—so, this $11 million mistake didn’t make much of a difference in the long run.

photograph of downward trending report, pinned to a cork bulletin board

7. A $37 million missed Excel cell

Emerson Construction Company was thrilled to be selected as the lowest bidder on a 2003 contract with the U.S. Army Corps of Engineers to build a barracks at Fort Hood, Texas.

Their excitement turned to dismay, however, when they realized their bid calculation somehow skipped a single cell—$3.7 million for electrical work.

The company got off easy, however, when the government allowed it to retroactively add the missing $3.7 million to their bid total. A rival contractor protested the fact that Emerson was allowed to correct its mistake, but the courts ruled in Emerson’s favor. Even with the addition of $3.7 million, their bid would still have come in lowest, if only barely.

photograph of woman standing in front of colleagues, giving thumbs down

8. MI5 accidentally bugs 134 telephone numbers

According to an old joke, “military intelligence” is a contradiction in terms. In 2011, British counter-intelligence service MI5 did their best to prove just that.

Because of a formatting error in one of its spreadsheets, MI5 mistakenly applied for user data on phone numbers ending in 000, instead of the actual three digits. As a result, the agency collected completely irrelevant data from 134 unsuspecting (and innocent) citizens.

photograph of military personal working in secure server room

In reporting the blunder, MI5 assured the public that the data in question had since been destroyed. They also promised in future to manually proof-read all requests for user data. Unfortunately, during the same report, MI5 had to admit that 927 other data requests had been made without proper authorization.

9. Influential economics research paper proves less than Excel-lent

Noted Harvard economist Carmen Reinhart and Ken Rogoff created a significant stir in 2010 when they presented a research paper entitled “Growth in a Time of Debt.”

At the time, the world was still reeling from the global economic meltdown of 2008. Reinhart-Rogoff shared their dismaying findings that economic growth slows dramatically whenever a country’s debt exceeds 90 percent of its GDP.

The paper proved extremely influential for the next three years, until a University of Massachusetts professor gave his graduate students an assignment: examine a published economics paper and try to replicate its contents.

man and woman in a meeting gesture impatiently and expectantly at another woman who appears to be frazzled or stressed

Student Thomas Herndon chose the Reinhart-Rogoff paper. After checking and rechecking his calculations, he told his professor he could not make the figures add up. Check again, he was told. After several more back-and-forths, the professor finally suspected something was amiss.

Sure enough, it turned out that Reinhart and Rogoff, in building their spreadsheet, somehow managed to include data from only 15 of the 20 key countries they had chosen. Once the other five countries were incorporated, the overall findings were far less dramatic.

In an official statement, Reinhart and Rogoff admitted, “It is sobering that such an error slipped into one of our papers despite our best efforts to be consistently careful.” When it comes to Excel, those are words to live by.

10. Banking giant jumps the gun

On November 1, 2005, Australian bank Westpac was poised to announce its greatest-ever 12-month profit: a whopping $2.818 billion. Not surprisingly, CEO David Morgan was feeling quite chipper. “I was in my office thinking what an enjoyable 48 hours I had ahead of me,” he recalled.

photograph of man and woman picking color swatch printed on paper

That afternoon, however, Morgan’s bubble burst. In preparation for the profit announcement, the company had sent an email to 37 analysts from seven brokerages, and had attached a spreadsheet outlining the previous year’s results. Unfortunately, details of the as-yet-secret profits were embedded in the template they used for the spreadsheet. Two of the analysts quickly contacted the bank to inform them of the blunder, but by then it was too late. The company was forced to halt trading on its shares and quickly pull together its profit announcement earlier than planned—while also admitting its mortifying mistake.

Stay off the disaster list. Get Sheetcast

As we have seen, a seemingly insignificant Excel oversight can have shattering repercussions. While no system is completely foolproof, Sheetcast can help your company avoid many of the most common—and potentially costly—Excel pitfalls. Stop reusing templates, which may contain hidden (and sensitive) data. Go from spreadsheet to web app.  Streamline and refine your data collection workflows, to avoid cut-and-paste errors or other faulty inputs. If you already know Excel, you can create secure and elegant web apps in minutes with Sheetcast. Visit the website for full details!

photograph of young professionals at work happy or excited about something happening on the laptop


More Articles:

Seven Essential Ways to Protect Your Spreadsheet

Too many of us are cautious in our daily lives, but cavalier with the safety and security of our spreadsheets.

Why Do People Still Use Spreadsheets?

Microsoft Excel debuted on the Macintosh in 1985 and came to Windows in 1987. Three and a half decades later, its name remains virtually synonymous with the very concept of “spreadsheets.”

Excel Heroes: Gašper Kamenšek

Discover Gašper Kamenšek's journey from college student to Excel MVP. His passion for Excel ignited during Microsoft Office classes, leading to a career shift and a thriving community involvement. Explore his experiences, insights, and adventures, from overcoming toxic work environments to becoming a sought-after speaker. Dive into his love affair with Excel and the ever-evolving landscape of data analysis.

Bulgaria Excel Days 2024

Sheetcast proudly announces their lead sponsorship for Bulgaria Excel Days 2024, demonstrating their dedication to the Excel Community. Join experts Ken Puls, Gašper Kamenšek, Alan Murray, and others for three days of Excel insights, presentations, and masterclasses. Don't miss Alex Martin of Sheetcast, premiering advanced new functions and workflows. Bulgaria Excel Days 2024 runs April 23-25 in Sofia, Bulgaria.

Excel Heroes: Crispo Mwangi

As the only Excel MVP in East, Central, and Southern Africa, Crispo Mwangi stands out as an Excel Influencer, business owner, and host of an MS Excel Forum, making his skills highly sought after. Despite his many commitments, this Kenyan luminary published his latest book, "Excel with PowerQuery and ChatGPT.

Excel plus Sheetcast as Your Ultimate Spreadsheet.com Alternative

Amid Spreadsheet.com's closure, Sheetcast provides a reliable solution, an Excel add-in. Created by a company of 15+ years, Sheetcast offers more than a quick fix. It pioneers innovative data management and application development, providing a secure path for those impacted by Spreadsheet.com's shutdown.

Customers Scramble for Alternatives as Spreadsheet.com Shuts Down

With Spreadsheet.com closing its doors on May 31, users are actively seeking alternatives. Sheetcast, an Excel add-in, stands out as the top solution, providing advanced capabilities and a seamless transition to reconstruct workflows into customized web apps. Sheetcast provides a smooth solution to Spreadsheet.com's shutdown

Advanced Data Visualization Techniques in Web Apps from Excel

If you’ve ever viewed a report or infographic powered by Excel-generated graphics, you recognize that the time-tested spreadsheet application has some powerful tricks up its sleeve in terms of data visualization. Bar charts, pie charts, scatter plots, pivot tables, and more

Excel Heroes: MrExcel Turns 25

Exactly 25 years ago, in 1998, Jelen published his first in a series of weekly Excel help articles at his brand-new website MrExcel.com (hardcore fans can still read that debut article thanks to the Wayback Machine). Soon afterward, he launched the MrExcel Message Board, an online community for Excel enthusiasts like himself.

The Evolution of Efficiency from Excel to Web App

For decades, Microsoft Excel has been a foundational component in the way global businesses collect, analyze, track, and report data. As powerful and flexible as Excel is on its own, however, it can now also serve as a stepping-off point to something even more dynamic and efficient.

Excel Heroes: N-nyiimock Bitanyanmi

N-nyiimock Bitanyanmi is a welcome and familiar face in the online Excel community, where he often goes by the name Justice. Behind his enthusiasm, knowledge, and eagerness to learn, however, lies a surprising fact: until he was almost an adult, he had rarely laid hands on a computer.

Tips to Prevent Data Entry Errors in Excel

With Excel, your formulas, charts, and reports are only as good as the data you enter. So, if you’re responsible for entering a vast data set, it’s important to minimize the risk for error.

How to use forms in Excel … plus something better

Excel forms have improved my life. Now, I know there’s something even better (stick around to the end of this tutorial).

Co-authoring in Excel: Tips and Pitfalls

For years, Excel users have been able to collaborate on shared workbooks. By making it possible for multiple users to work together on a single file, Microsoft unlocked countless ways to boost efficiency and productivity.

It’s Time for Excel to Evolve: From Spreadsheets to Web Apps

The Necessary Evolution from Excel Spreadsheets to Web Apps. Like many of the greatest technologies of our time, spreadsheets can be our salvation or our downfall – and with great power comes great responsibility.

Want to Convert Excel Spreadsheets to Web Apps?

Sheetcast enables you to convert Excel spreadsheets to web apps directly in Microsoft Office, a tool you already use every day. Sheetcast is affordable, easy to learn, and has hundreds of potential uses (limited only by your imagination).

Do You Use Any of These Five Excel Features? If So, Try Sheetcast

Maybe you’re a bit of an Excel guru. Your workmates frequently marvel at your ability to get the most out of the app, employing functionality they never even knew existed.