Every workplace has its own rules and culture, but there are some things you shouldn’t be caught doing anywhere.
1. Come In Late

Keep ignoring your alarm clock, and you could soon be conducting your own funeral dirge. Constantly showing up late gives the impression that you’re job doesn’t matter enough to you to make it a priority, and if employers see that, why should they make paying you a priority, either?
2. Quit out of Emotion

People spend the single most burst of time at their jobs, which means it’s where they interact the most with a set group of people. Over time, emotions will spill over when personalities clash, but quitting because of, or in spite of, that is not professional at all. Write a letter.
3. Bad-Mouth Former Colleagues

Say something negative about Jim in accounting and your coworkers might laugh, but on the inside, they’ll be thinking what you also say about them. If you don’t want to get a reputation as a trash-talker, don’t trash-talk. And even if you think you’re safe halfway around the world, you never know the full extent of Skype conversations.
4. Complain about the Job

To put it really bluntly: if you don’t like the work, get out. There’s a lineup of people behind you who would gladly take your job if you really don’t want to be there, so evaluate just how happy you are and how much you can abide. And remember that if you do decide to start looking elsewhere, keep your lack of enjoyment to a minimum because nobody likes a complainer.
5. Be Indiscreet about Cellphone Use
Everyone uses their cellphone at work and everyone knows everyone else is using theirs, but that doesn’t give you a free pass to whip it out and play Flappy Bird all day long. Unless your business requires you to be on a cellphone—in which case you should be using it for work-related purposes—then remember the company’s not paying you for your iPhone skills, and excuse yourself to the bathroom to send a text.
6. Lie

We’re not saying you should be brutally honest with everyone about everything, but to be transparent when it matters. Your boss knows perfectly well that there’ll come a time when you don’t know something, and it’s better to just admit that instead of making a mess of things. But if you do make a mistake, own up to that, too—it just looks better.
7. Use the Computer for Personal Reasons

Just like your smartphone, you’re not getting paid to tweet in real-time or share juicy articles on Facebook. If you must check your personal email or use social media, remember to use Google Incognito and be prepared to close the tab as soon as anyone comes within 20 feet of you.