1. Treating Sick Time as Extra Vacation Time

Food poisoning again, is it?

Everyone’s tempted to call in sick just to get an extra day off. Just don’t think you’re fooling anyone. If you make a habit out of calling in sick every time you need a break, you should probably spend your ill-gotten days off cruising the classifieds.

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Vicky Oliver, author of Bad Bosses, Crazy Coworkers & Other Office Idiots, named the fake sick day as a major reason bosses fire their employees.

Remember the adage that half of life is showing up, she told Business Insider. Our advice? If you’re really intent on faking a sick day, be sure to silence the questions before they start. We recommend a line like, “It’s coming out of both ends!”

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This only works about once a year, by the way. And don’t try it on the Monday after the Super Bowl.

2. Openly Looking for a New Job on Company Time

Employers want to know that you’re invested. If you spend half the day emailing out resumes, it’ll be obvious to them that you’re over your current position.

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Don’t think that they won’t find out, either. All company emails are fair game for the IT department, who may even have a standing order to alert management when an employee sniffs around for a new job on company time.

3. Mistreating Customers

This should be obvious, but thanks to the magic of the internet, we know that the lesson hasn’t sunk in everywhere.

A Reddit thread asked managers to share their stories of firing employees. User Mirraklewhippn remembered a server who was obviously ready to move on.

Getty Images News / Joe Raedle

“New-ish server was dealing with a complaint a customer had with their BLT,” Mirraklewhippn wrote. “Rather than having me talk to the table, he took a bite out of it and said, ‘I’m not seeing the problem.'”

4. Chronic Lateness

The snooze button is your enemy.

Business etiquette starts with being on time. That’s what Rosalinda Oropeza Randall, author of Don’t Burp in the Boardroom, tells us, anyway.

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Punctuality is critical, Randall told Business Insider. “The professional thing to do is to arrive on time, ready to do what is expected. It’s not like they just sprung this job on you.”

5. Flirting with Harassment

It’s probably best to keep your professional life, well, professional. Comments about someone else’s appearance have no place at work, and could even cost you your job. Watch the video below to learn more about the comments to avoid if you want to remain employed.

6. Letting that Pervasive Negative Bias Show

The world may be hurtling toward disaster, life may be a bleak and empty march toward the grave, and you might have grown up to be nothing more than a disappointment. When you’re at work, though, you’ve got to find a way to grin and bear it. At least learn to plaster a vaguely human grimace of dedication on your face.

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No one likes a Negative Nancy. Bosses especially. They got where they are today either by being true believers in the Company or by being Patrick Bateman-style sociopaths. Either way, they won’t look too kindly on constant negativity.

Read your Nihilist Arbys tweets at home.

7. Indulging in Your Social Media Habits on the Clock

Most professionals work with computers these days. Most human beings with computers mostly use them to browse social media.

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That’s a toxic combination, at least from your employer’s perspective. Check your tweets on your own time and on your own phone.

8. The Grunge Look

Lots of today’s professionals grew up in the ’90s, an era that elevated poor hygiene to the level of art. The unwashed look can cause a problem in the boardroom, though.

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Poor hygiene and sloppy clothes scream, ‘I don’t care!’ Randall told Business Insider. Being a slob is “a surefire way to put off those around you,” she said.

If you’re a programmer or a “creative,” you might have a little more leeway to look like a reprobate. But why take the chance?

9. Indulging in Office Gossip

Every manager of human resources has a story about gossip. The subjects of that gossip are rarely the ones who end up packing up their desks.

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Just remember, spreading rumors can hurt your coworkers’ (or, worse, your superiors’) feelings. When people get hurt feelings, they might call the HR department. When the HR department gets the whole story, you might end up looking for a new job.

10. Refusing to Put Down the Phone During Meetings

These days, we spend most of our waking hours staring down into the slabs of glass and circuitry in our hands. We check social media during family dinners. We glance through work emails when we should be falling asleep.

But there’s one place where cell-phone addiction can really take a toll on your future, and that’s the corporate meeting room. Your high school drama teacher was right. Eye contact really is important.

During meetings, put your phone away. Otherwise, you might have to use it to look for jobs on Craigslist.

11. TMI

Most managers are sympathetic to the fact that their workers have lives outside of work. When you’re going through a tough time, they’ll cut you some slack.

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But if you just can’t stop moaning about your divorce, and that starts to distract your coworkers, you’re on the way to a swift and decisive firing.

12. “Embellishing” Your Resume

No one really checks all those degrees you claimed on your resume, do they? Yes. Yes, they do.

Distractify

Bruce Hurwitz, president and CEO of Hurwitz Strategic Staffing, told AOL Finance about an employee who thought he could get away with padding his resume.

This poor guy’s resume said he had a CPA license. He did not.

“He had the job, was doing a good job, but was fired on the spot when his boss found out he had lied on his resume. The job didn’t require a CPA, but the boss checked to see if he had it anyway. Even though it wasn’t a requirement, it reflected on his character.”

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Imagine if this guy hadn’t been doing a good job. Any lies on your resume provide an easy excuse to fire you, even if your bosses have it out for you for something totally unrelated. Keep it real on the resume.

13. Having a Foul Mouth

Cussing is fun. What’s not to like? A well-placed curse word can really drive home your point.

But if you want a long, successful career, you might want to practice “heck,” “darn,” and “gosh-dang.” You can even break out a “goodness gracious!” when it’s really warranted.

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That’s because swearing is generally considered super unprofessional, even in today’s post- South Park world.

Using foul words or questionable language is not only a bad habit, but in most places of business, it’s still considered unprofessional and can even land you in Human Resources for a little chat, Randall told Business Insider.

14. Stealing

You might think no one will miss a few pens or a roll of toilet paper. Maybe they won’t. But if they find out you’ve been raiding the company supply closet, that won’t matter.

Nikki Ormerod

Employers don’t like thieves. Even a minor theft can land you in the unemployment line.