'The guy who cost the company $3 million dollars': 20+ Employees who made colossal mistakes at work

Author image for Remy Millisky
Remy Millisky • Writer and Editor
Jul 9, 2025 11:00 AM EDT

Many mistakes can be forgiven, but in the workplace, sometimes it can cost you your job. 

If you're a solid employee, your company will probably overlook most of your mistakes, even the really severe ones. Some people accidentally cost their company thousands of dollars, and the bosses just shrug their shoulders and carry on with their workday. But other times, that manager needs someone to blame, and if they aren't totally happy with that employee, their head is on the chopping block. 

These stories might make you feel better about the mistakes you've made on the job. At least you've (probably) never lost your company millions of dollars, bad-mouthed an important client over email, or sent out the wrong item to print out hundreds of copies before realizing the mistake. 

Next, read about the aspiring influencer whose friend unfollowed her, saying that they don't like seeing her become a "living billboard": "It completely took over her personality." 

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  • 01

    "What is the worst mistake you made at work?"

    AlabamaPickleFar... I replied to the sender of an all staff email instead of my buddy stating "Does she really have to send this sh to everyone in the company?". I took the long way around the senders office for a while after that one.
    via u/AlabamaPickleFarmer
  • 02
    [deleted] I accidentally set off the silent police alarm because nobody told me what it was. This costs €5000 every false call. I did it twice on one day.
    via u/[deleted]
  • 03
    captainmagictrous... I missed the deadline on an important grant application. But in my defense, I'm not very good at my job.
    via u/captainmagictrousers
  • 04
    AR... Once I locked the keys in my work van.....on the day I received the work van....and the only instructions I'd been given were "This is the only key I have for this. Don't lose it."
    via u/ARealBillsFan
  • 05
    Edit: Since this gained some traction I want to add that it was like a 88-90 dodge caravan/Plymouth Voyager. The van had some type of mechanism where in the event it was left unlocked and undisturbed for a
    via u/ARealBillsFan
  • 06
    certain period of time the door locks automatically engaged. I heard them click from the ladder I was standing on like 20 yards away. I knew that sound was bad news.
    via u/ARealBillsFan
  • 07
    ITARSUM I put mustard in someone's salad instead of honey mustard :(
    via u/ITARSUM
  • 08
    MidnightSG After an amazing promotion at my dream job of 10 years, I told a coworker how much money I make. They must have told everyone. My boss informed me how unacceptable what I did. was. The next week they fired me with no reason. (I live in an "at will" state.)
    via u/MidnightSG
  • 09
    32r... I worked a climbing wall as a belayer. We tied all of the knots ourselves every day, and did double checks with each other to ensure they were safe. One day we had a few different people come in to belay while we were at lunch. We return and get back to work. I've got a small family with me and
    via u/32redalexs
  • 10
    their 5-6 year old daughter is almost at the top of the wall when I look up and notice the knot attached to her harness is coming undone. I just calmly belayed her down, not mentioning the knot to keep everyone calm, and then I tell them I'd just like to retie the knot just for my own preferences.
    via u/32redalexs
  • 11
    I'm not sure when the knot started coming apart, i should have checked it after coming back, but I had assumed it was the same knot I'd tied earlier that day. Turns out one of the people who substituted for me retied the knot improperly while I was gone. Still my fault for not checking, but at least it wasn't my knot that sucked.
    via u/32redalexs
  • 12
    Can't describe the horror of looking up at this child and realizing that the knot holding them could fail and they could fall 30+ feet on my watch.
    via u/32redalexs
  • 13
    thndrchld root@prod-server:/var/www/our-app# rm -rf cache /*
    via u/thndrchld
  • 14
    See that space? The one between 'cache' and '/*'? I didn't. And that's how I learned not to log in as root. Explanation for non-techies:
    via u/thndrchld
  • 15
    I was logged in to our production server (the main one the one everyone -- uses) as an unlimited-power administrator. I was trying to delete some junk files, but accidentally deleted everything. EVERYTHING. I nuked the entire system including the operating system, all documents, and every user account -- with a misplaced space.
    via u/thndrchld
  • 16
    rm deletes files. -r tells it to recurse through all folders. f tells it not to confirm file deletion -- just do it. cache/* would tell it to only operate on all files in the 'cache' folder. But I didn't type cache/* I typed cache /* That space separates 'cache' and '/*'. That means that it would remove 'cache', then remove '/*'. On a linux system, '/' refers to the top level folder. Literally
    via u/thndrchld
  • 17
    everything on the system is in '/'. The '*' means "every file under". So, translated from native dork, we have the command: "delete everything in the cache, then delete everything in the system, but don't bother confirming it. Just do it." "Now, why would there be a 'murder everything in sight' command," you ask?
    via u/thndrchld
  • 18
    Well, on newer systems, rm has protection built-in to prevent this from happening. It will utterly refuse to delete '/' unless you override the behavior with a special option However, this wasn't a newer system. This was a system with no such protection. So, when I issued the command, it just started happily slaughtering every file it could find without complaint, right up to the second it started
    via u/thndrchld
  • 19
    deleting things it needed to continue operating. "Hmmm... this sure is taking longer than I'd exp--- HOLY CRP!! NO NO NO NO NO NO NO NO NO"
    via u/thndrchld
  • 20
    Mr5wift Sent off a file to print that was wrong, cost a few thousand to reprint. Woops.
    via u/Mr5wift
  • 21
    REIND JULY DOE NE 4270320 100 D PEDRAL RESERVE NOTE WE42703207 A ES COPY ODRED DOLLARS ARE UNITED STATES OFAMERICA L FOR ALL DERTS, PUBLIC AND PRIVATE 100 MEU THE VITED STATES FAMERICA DD WE42703207A 100
    via Katelyn Perry For Unsplash+

    The image does not depict the actual subjects of the story. Subjects are models.

  • 22
    Elliewatsonn Working in tourism, i give tours to generally a group of 70-80 tourists of a very famous structure. My roommates at the time were 3 welsh rugby players, absolutely crazy We all go out one night, i had a bit too much salsa, and go back to pass out for work the next morning. I am a little late so a quick brush my teeth and bolt out the
    via u/Elliewatsonn
  • 23
    door. Im riding the metro to work, and everyone is giving me very odd looks. I down 3 tylenol, down a bottle of water and head to my first group for the day without think anymore of it. About thirty minutes into the tour, i hear snickering and laughing from the younger kids. Even some adults were looking at me trying not to laugh. A guy comes up to me in the middle of me explaining
    via u/Elliewatsonn
  • 24
    where the structure got its sandstone and says "Hey man, you have drawn on your face, and its glittery". I kind of laugh it off in disbelief, but he shows me on his iphone camera. I sprint to the bathroom to wash it off, plotting my revenge on my roomate, which i eventually got.
    via u/Elliewatsonn
  • 25

    If only they could've seen the confusion on the clients' faces after opening the wrong piece of artwork

    redheadedfury I once was shipping 2 pieces of art to Europe, different countries that were nowhere near each other. Wanna guess which dumdum switched the labels???? Was not fun
    via u/redheadedfury
  • 26
    trying to reroute them and explain to the clients that it went to the wrong country.... Im very careful with shipping labels now :)
    via u/redheadedfury
  • 27
    Ravenne14 forgot to include the terms and conditions in an email to a customer, and ended up having to do a write off to the tune of about $1300 because "she wasn't made aware of the time limits." Still makes me sick to my stomach.
    via u/Ravenne14
  • 28
    NO... I was marking piling locations for a large addition to a building. I marked one piling in the wrong spot. The driller drilled, and the concrete company poured the piling (approximately 50' from the surface to the bottom of the piling). They discovered it after the fact when they were getting ready to set the steel. They
    via u/N0_R0B0
  • 29
    had to re drill (the drilling rig had already been broken down to go to the next site) and re-pour (the concrete company had to be called back in). I had marked 49 of the 50 pilings perfectly. Unfortunately the one I marked wrong meant our small company had to eat over $10,000 worth of work. A lot of money for a small business.
    via u/N0_R0B0
  • 30
    Cheezburger Image 10527141632
    via Getty Images For Unsplash+

    The image does not depict the actual subjects of the story. Subjects are models.

  • 31
    [deleted] I was earning six figures with an office overlooking downtown Oakland with a job that had little or no responsibility. Chronically bored, I complained to my boss that I felt like my job was pointless and redundant. She believed me.
    via u/[deleted]
  • 32
    Ric... Not me personally, but one of my coworkers has a habit of sending emails to the wrong people if they had same first name. So there's Brian A and Brian B.. Brian A. is one of our sales guys, and he and my coworker had a long back and forth with the entire sales team about how they were basically going to screw over Brian B., a major multi-million client of ours.
    via u/RiceandBeansandChees
  • 33
    Same old sales sh, smoke and mirrors, essentially Brian B. wasn't going to get his money's worth for the $$$$ he spent. It was incredibly confidential, super unethical, and possibly included stuff that we could get sued for. Things that should never be in writing. She ended up copying Brian B. on the entire email chain.
    via u/RiceandBeansandChees
  • 34
    Our sales director ended up swearing loud enough for me to hear it from across the office, and he promptly took a week vacation a few days afterwards. The fact that she wasn't fired was one of the reasons why I left that company.
    via u/RiceandBeansandChees
  • 35
    Kaz3000 I worked in a major UK retailers head office as first line/second line IT support. Was training a noobie on how to give permissions to files, folders etc. general IT stuff. When it was the trainees turn, I asked her to change permissions on a folder I created just to show her, she didn't select the
    via u/Kaz3000
  • 36
    actual folder, instead it was the root directory. Ended up changing permissions for all in-house staff on that particular server, couldn't make changes to files, folders... I wasn't even aware she'd done this until users started ringing up saying they couldn't access their work.
    via u/Kaz3000
  • 37
    Was pretty fun trying to work out whats gone wrong and then trying to explain it!
    via u/Kaz3000
  • 38
    Ciaranleigh I work at a jewellers and i pressure tested an expensive watch that didn't have a screw down button. Customer came back 3 days later complaining it wasn't working. Water had gotten into the watch, rusting the whole movement. We had to replace the watch.
    via u/Ciaranleigh
  • 39
    32redalexs I worked at a restaurant that sold some gluten free options, which usually meant that they wouldn't be given a certain peanut sauce with a certain meal they could order. A woman comes in and wants this meal, intensely making sure I'm aware she can't have any peanuts and is allergic. I assure her that there will be no peanuts because the
    via u/32redalexs
  • 40
    peanuts were in the sauce and we simply wouldn't give her that sauce. Turns out I had been trained improperly and there were peanuts in the meal itself. Woman takes a bite, notices the peanuts, and freaks out. Fortunately for me she was kind of a b and was really exaggerating her allergies. She was fine, but
    via u/32redalexs
  • 41
    to this day I think about if she had actually been severely allergic. All I received was a literal slap on the wrist by my manager, didn't even get scolded.
    via u/32redalexs
  • 42
    Tenushi I had to generate an external message to notify hundreds of thousands of people that there was an outage, and a teammate had changed the email template incorrectly. The thing went out with a subject line, which seems pretty inconsequential, but it did not reflect well on me or my team.
    via u/Tenushi
  • 43
    Mssorepaws I put diesel in the hydraulic fluid tank.
    via u/Mssorepaws
  • 44
    IrishGuyGolfer I introduced my boss to my wife. Now she's my ex-wife and his current fiance.
    via u/IrishGuyGolfer
  • 45
    MichaelMoore92 Ex British cop: I didn't make many mistakes because I was so scared to mess up I triple checked EVERYTHING, but I witnessed another new copper accidentally press her panic alarm in the station. The alarm basically transmits your voice down
    via u/MichaelMoore92
  • 46
    the radio for 20 seconds, without the need to hold down the radio so you could use both your hands and still talk. When it's pushed, you're looking at a poorly constructed version of 'avengers assemble' so everyone jumps to their feet and ready for the world to end. Then all you could hear was "oh sorry! Sorry!" Down the radio over and over again.
    via u/MichaelMoore92
  • 47
    She got told off by the sergeant but she was only a few days in and it was a genuine accident so it wasn't too bad.
    via u/MichaelMoore92
  • 48
    Cheezburger Image 10527177728
    via Ahmet Kurt For Unsplash+

    The image does not depict the actual subjects of the story. Subjects are models.

  • 49
    TheEpicBlob Accidentally miss representing sales figures to my MD, him finding out, thinking I was intentionally lying and giving me a written warning/final warning. I hated that month, but completely owned up once the error was found which I think helped soften the damage. Still here tho..
    via u/TheEpicBlob
  • 50
    OscarSlenderman As a painter, I was putting up this expensive English Wallpaper(over 100USD per roll) in a huge villa. I've been doing this for years so I Was doing it on routine, took me 15 rolls before I realized I had put them upside- down... Legit thought I was going to have a panic attack
    via u/OscarSlenderman
  • 51
    barnaclescar I missed my Uncles funeral for a work promotion but was then fired the next day.
    via u/barnaclescar
  • 52
    DevilsPajamas Trying too hard and end up doing more work than everyone else because of it. Didn't get rewarded with anything.. just...more work..
    via u/DevilsPajamas
  • 53
    -Specter I was supposed to verify dimensions for everything. I saw that several dimensions matched for one equipment so I just assumed it was all correct. Later into the fabrication stage of the project I found out that one of the most critical dimensions did not match. Meaning the entire sh was off by 7+ inches. All my fault! My manager taught me
    via u/-Specter
  • 54
    an important lesson that day. He told me "Look. A mistake was made. There is no reason for you to dwell on the mistake made. Instead come up with a viable and effective way to solve it." In other words II don't dwell on the sh that has already happened, instead focus on what you CAN do to improve the situation". I was able to fix everything by making a
    via u/-Specter
  • 55
    small modification to a structural component. The project was still completed within the deadline.
    via u/-Specter
  • 56
    clocksailor My boss slept through a massive screenshare presentation and I ended up having to take over for him at the last minute. While sharing my screen with people from all over the country, a text message
    via u/clocksailor
  • 57
    from a friend I'd had a heated board game session. with the previous night appeared on my screen. Now everyone at my old job knows I "couldn't talk sh if my a was on my face."
    via u/clocksailor
  • 58
    Baconatorboy Left the sink on with the hose in the mop bucket and flooded the entire lobby of a Mac'n'Don's in about 3 inches of water. Was fun.
    via u/Baconatorboy
  • 59
    RockwellTK421 As part of a promotion we were rewarding accounts with in store credit. Made a mistake in the CSV file I was using for an upload, did not spot check, and ended up giving away the equivalent of $2million. Found my issue 5 minutes later and reversed the issue, but some of the in-store credit had already been used by customers.
    via u/RockwellTK421
  • 60
    navin_johnson I screwed up by fixing a problem. I got hired to do logistics for a large retail company. I worked with the buyers to get the stuff they bought into our warehouses stateside. It was pretty easy-we had a freight forwarder who did all of the work-i just had to coordinate it. After the first few shipments, i see the bills for the shipping and I see it-all
    via u/navin__johnson
  • 61
    of the items we were being shipped (and there were ALL kinds of different items) were being slapped with one duty code-and of course, that duty had a zero percentage. For those of you who do not know, you have to pay a "duty" (basically a tax) on certain items you import. Different items have different duty rates, and its the reponsibility of the buyer to
    via u/navin__johnson
  • 62
    recognize and pay the correct duty for the items. you are shipping. I check past invoices, and this duty code goes back years. We have basically been ripping the US gov off for shipping these items for years. Determined to not be stained by this and do my job, i approach my supervisor and inform them of this. I then say I am going
    via u/navin__johnson
  • 63
    to classify correctly all of our stuff from now on, so expect larger $$$ bills now, because we are going to start paying the duty we owe. Supervisor said OK. So I do. Well, the sharp increase in our bills must have triggered US Customs because a few months later our warehouse was raided.
    via u/navin__johnson
  • 64
    They went back through years of "fraudulent invoices" and determined the company owed over 3 million in unpaid duties and fees. Company had to cut a check to the gov for that amount. The CFO even showed me the check.
    via u/navin__johnson
  • 65
    Worst part was, all this happened during the 2009 economic downturn and the company was already bl ding money and talking about layoffs, so I sort of became a scapegoat of sorts. "The guy who cost the company $3million dollars". All because I "fixed" a problem.
    via u/navin__johnson
  • 66
    dandaman64 Worked at a photo lab, one day around the end of my shift I had to load new photo paper in a dark box (the photo paper needs to stay unexposed to light or else burn marks appear all over the printed photos), and I didn't close the dark box properly. The first few feet of the paper was exposed, as well as the edges of every photo, making burn
    via u/dandaman64
  • 67
    marks all over the pictures. Inconveniently this was right in the middle of a customer's order that was 500+ pictures. I had to stay roughly 1.5 hours after my 8 hour long shift to load another new roll of paper, throw out the exposed one, and reprint the last 200+ photos with my manager.
    via u/dandaman64
  • 68
    - tl;dr Exposed light sensitive photo paper, made burn marks on 200/500 of a customer's photos, had to stay an extra 90 minutes, luckily wasn't reprimanded.
    via u/dandaman64
  • 69
    MrFluffPants1349 One morning when I was a projectionist I was distracted as I was I the middle of a fight with my girlfriend at the time over text. I flipped the breakers to the machines, and even double checked, but somehow missed the one that went to the vent fan for one of the projectors. Because of this the machine overheated,
    via u/MrFluffPants1349
  • 70
    melted some really important parts, and cost the company over a thousand dollars in damages. I was terminated as a result, and learned the hard way that complacency kills.
    via u/MrFluffPants1349
  • 71
    keigo199013 At my first job (computer repair shop), I was backing up a customer's documents to a dvd before doing a format & reinstall. I was the only tech working that day and we were swamped. I didn't verify the data on the disc before wiping and reinstalling Windows like I normally did (I was young, foolish and overworked).
    via u/keigo199013
  • 72
    Turns out that the data didn't burn over correctly. User lost his data. I apologized profusely. He was very understanding, said it was some older stuff that wasn't super important. Because of this, I began backing up my customer's data on a portable HDD and verifying on a second computer from then on. Still what I do to this day.
    via u/keigo199013
  • 73

    A kitten is more important than a forklift!

    MissThystle Backed a forklift half way off the loading dock while it was carrying a soda machine because I was saving a kitten that had gotten stuck under the machine. In my defense I pointed out that I didn't back the forklift totally off the dock and no one had ever shown me how to operate one...they taught
    via u/MissThystle
  • 74
    me how and then banned me from driving them. The kitten went home with our really scary looking dock foreman and lived happily ever after.
    via u/MissThystle
  • 75
    HellolAmHawt Taking this job. It's awful and my boss is continuously doing things to trap me here. For example, I have sick days, but he wants to know about them in advance (so I guess, plan to be sick). Because of this, even when I get interviews for dream jobs (this job is only vaguely related to my intended career path), it's impossible. to get to them. The one time
    via u/HellolAmHawt
  • 76
    I did call a sick day I got a sit down meeting about my place in the company. I need this cash, so I can't risk losing this job until I have another lined up. Beyond that he does this by giving me raises (I know, the horror--but it sets up unrealistic expectations should I leave), continuously (pitifully) telling me how integral I am to the company (guilt city), and signing me
    via u/HellolAmHawt
  • 77
    up for extended education (without asking, and already paying for it and implying it's a requirement to do things. off-hours). If I could go back, I would quash all the "it'll be good for your resume" BS and just keep bartending and applying for dream jobs, because right now I feel like this is the rest of my life and it's terrifying.
    via u/HellolAmHawt
  • 78
    Tony Danzer I work at a doggy daycamp and one time I gave a woman the wrong dog. The worst part is she almost didn't realize it wasn't her dog and nearly took it home.
    via u/Tony Danzer
  • 79
    [de... I had a job where I had what I refer to as a "helicopter boss." One time I sent an email with "Good morning" in the title, and I was reprimanded because I neglected to capitalize the "M" in "Morning." I was also spoken to about the way I sign my emails with "Regards" and that I should use "Kindest
    via u/[deleted]
  • 80
    Regards" or "Warmest Regards" instead. I wish this was a joke, but I was actually written up for this. From that point forward, my boss actually demanded that I send her all outgoing emails first, so she could "review" them, and then she would send them back to me and then she would make me send it to the client, while also BCC'ing my boss so she
    via u/[deleted]
  • 81
    could make sure I didn't alter the emails further. Once again - I wish I was joking. As I've gone through my professional career, I've come to find that there was nothing wrong with the way I wrote emails. She was just an a hole. In all seriousness though, the worst mistake I did on that job was accidentally delete a $1300 photo sh ot from our files. It was a pure
    via u/[deleted]
  • 82
    accident and I have no idea if/how I actually did this, but I took responsibility for it but had no solution. I caught grief over that for months. Maybe 3 months later, we would be sitting in a meeting and I was going over everything I was working on, projects and whatnot, and my boss (in front of everyone) blurts out "AND DID YOU GET THE PHOTOS!!!???!!"
    via u/[deleted]
  • 83
    She did this multiple times, in various meetings. "AND THE PHOTOS??!!?" even when the meeting was 100% unrelated to the photos It turns out she had a cd with the photos on there, sitting on her desk. The entire time. She was a raging
    via u/[deleted]
  • 84
    EpicMeatSpin I worked for a company that had a lot of large trucks/other vehicles that they had to keep fuel usage logs for, along with mileage. My understanding was that they had to submit this information at certain points (likely quarterly) for tax purposes. On my first go with it, I screwed everything up. The reports were late and the company got fined.
    via u/EpicMeatSpin
  • 85
    I think the only reason I didn't get fired was because they were falsifying some of the information. A lot of the drivers didn't give a sh about keeping the logs and several of the trucks had broken odometers. Thankfully, I was never asked to work on those reports ever again.
    via u/EpicMeatSpin
  • 86
    shevrolet Not my mistake (thank god) but a former coworker recently lost a million dollars in the mail.
    via u/shevrolet
  • 87
    djw319 I was making a dessert for the table I was waiting and the last step in a long process was sprinkling cinnamon on it. I dumped way too much out on the dessert and without thinking I just tried blowing the cinnamon off, not thinking about the fact that I was going to feed this to a stranger. As I blew on the dessert a new table was
    via u/djw319
  • 88
    being sat and the mom saw me do it. She stopped and said loudly, and nasaly, "OH, MY GAHD!" I realized my mistake and remade the dessert. Then I found out the mom's family was sat in my section. I walked up to introduce myself and got a slightly higher pitch "OH MY GAHD" from the woman. I just said, "I know ma'am, I'm not happy about it either. Can I
    via u/djw319
  • 89
    bring you something to drink?" Surprisingly the rest of the meal went really well, and they tipped decently.
    via u/djw319
  • 90
    aportlyquail Do inventory. Missed $15,000 dollars of product at a client location two and a half hours away. Boss had to drive back. Wasn't fired but I still haven't lived that one down...
    via u/aportlyquail
  • 91

    This could've been bad...

    moosecliffwood One of my clients had a super NDA. Needed to take a screenshot, ShareX was set to automatically upload to imgur. Didn't realize it until I'd been doing it for a week and none of the delete URLs I eventually found in ShareX worked. Ffffff. FREAKED OUT, contacted imgur to get them removed, confessed to my supervisor
    via u/moosecliffwood
  • 92
    while feeling like I was going to puke. There was no concealing who the company was or what the work was in the screenshots. It was all extremely confidential. Didn't get fired or reprimanded.
    via u/moosecliffwood
  • 93
    Class08 I deleted the live database at work. Sat in the server room and cried. Two important lessons were had that day. 1. Do not have the live database and test database open at the same time when deleting the test database 2. This is why we have backups.
    via u/Class08
  • 94
    We lost a few hours worth of work. I used the experience to improve how often we back up. The feeling of walking down the open plan office to the server room as the database clients crashed on staff computers was not great.
    via u/Class08

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