Annoying your co-workers, while never a good idea, is one thing. But annoying your boss with your unprofessional habits could cost you your job.
To help you avoid letting your bad habits get the best of you, we asked experts to highlight some of the least professional behaviors you could demonstrate at work that will put your job on the line or cost you a promotion.
Here are 18 things you could be doing all wrong that may make your boss think you're not right for the job.
1. Showing up late to work
"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," she says.
2. Rolling in 10 minutes late to every meeting
Similarly, showing up late to meetings shows that you respect neither your co-workers--who showed up on time, by the way--nor the meeting organizer, Vicky Oliver, author of 301 Smart Answers to Tough Interview Questions and Bad Bosses, Crazy Coworkers & Other Office Idiots, tells Business Insider.
"Keeping people waiting can be construed as inconsiderate, rude, or arrogant," Randall says.
3. Being negative all the time
Repeatedly responding to suggestions with a pessimistic or contrary attitude can be construed as being uncooperative, Randall says. Phrases like "That won't work," "That sounds too hard," or "I wouldn't know how to start" should be avoided.
Similarly, complaining too much puts you in a bad light.
"While there may be times when everyone feels the desire to complain about the boss, a co-worker, or a task, voicing it will only make you look unprofessional," Randall says. "It's even worse if you complain every day, all day, from the moment you walk into work. Before long, people will go out of their way to avoid you."
"There's nothing as energy-draining as having to deal with a pessimistic co-worker," Rosemary Haefner, chief human-resources officer for CareerBuilder, tells Business Insider. "Things do go wrong, but even when they do, focus your energy toward what you've learned from a bad situation."
She points to a recent CareerBuilder survey, which shows that a majority of employers--62 percent--say they are less likely to promote employees who have a negative or pessimistic attitude.
4. Being a slob
"Whether you're at your desk or in the break room, being known as the office slob is never a compliment," says Randall.
When you clog the office kitchen sink and leave your garbage around, who exactly are you expecting to clean up after you?
"Leaving your mess behind shows lack of responsibility or consideration, arrogance, and immaturity," Randall says.
Similarly, your workspace can be a reflection of you, she says.
"If you're like me, who works well in a semi-messy environment, it can be inhibiting to be clutter-free. But with open cubicles or workspaces, the professional thing to do is to make some compromises," Randall says. "It would be disrespectful and inconsiderate to expect your co-workers to deal with your mess."
According to Haefner, employees who don't clean up after themselves can hurt their chances for a promotion in the eyes of 36 percent of employers.
5. Playing 20 Questions on every new assignment
There may be no stupid questions, Oliver says, but there are certainly annoying questions. These are the kinds of questions that prove you really don't want to do the assignment or illustrate that you only want to hear yourself talk.
"When you receive a new assignment, gather your questions, and pose them in an organized way," Oliver suggests. "Never just spout out question after question off the cuff."
6. Being on Facebook all the time
Being on Facebook every time your boss walks by looks really bad, Oliver says. Worse, griping about your boss and colleagues while you're on Facebook or letting slip anything that is highly confidential could get you fired.
7. Practicing poor hygiene and grooming
You want to look like you take your job seriously when you walk into work, and your hygiene and appearance play a role in that.
"Poor hygiene and sloppy clothes scream, 'I don't care!' and are a surefire way to put off those around you," Randall says.
Your boss may wonder whether your attitude about how you present yourself extends to your work, she explains, and you may be passed over for a promotion, overlooked when it's time to meet with a client or represent the company at a conference, and not invited to social gathering.
8. Calling in sick when you aren't
"Remember the adage that half of life is showing up," Oliver says.
You won't prove you deserve the promotion if you call in sick every few weeks.
9. Discussing your divorce (or other personal problems)
Oliver says there are two problems that come from openly discussing your divorce at work: "First, you just don't look like you are actively employed when you spend hours a day dishing about your ex. Second, you're discussing a personal problem at the office when you're supposed to be a maestro at solving problems.
"The place for disclosing confidences is outside the office," Oliver says.
10. Selling stuff
It seems like almost every office has one or two people who sell cookies for their kids. But Randall says that some companies prohibit soliciting at work because it takes up work time and places people in an awkward position. Breaking the rules could be grounds for firing.
11. Being distracted during meetings
"There is a reason why texting is illegal while driving: It's impossible to concentrate fully on two things simultaneously," Oliver says.
Texting, surfing the web on your laptop, instant messaging, emailing--doing any of these things during a meeting shows everyone else in the meeting, especially your boss, that you're not paying attention.
"They know that while your butt may be planted in the chair, your mind is roaming," Oliver says.
"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 says.
Swearing demonstrates to others that you aren't able to calmly and thoughtfully deal with a situation, and it could make you the last resort in an even more difficult or extreme dilemma, she says.
Haefner says that more than half of employers CareerBuilder surveyed consider vulgar language an indication that an employee is not ready for promotion.
"Consider learning some new adjectives," Randall suggests.
13. Making personal calls all day long
Talking or texting with friends or family on company time is unprofessional and could be against company policy, Randall says. What's more, doing it during a break is fine, but these correspondences should be kept out of the workplace, even the lunch room.
"You never know when your boss may walk by for an impromptu chat," she says. "What will they see or hear?"
"If the topic of conversation is of a delicate nature, be sure to keep it private. One overheard juicy tidbit can spread like wildfire," Randall says.
"Joining a March Madness pool can be fun and build camaraderie, but before you do, check the company's policies," Randall warns. "Even a friendly exchange of money can be considered gambling, which is illegal in some states and prohibited in many companies."
15. Being overtly cliquey
"Maybe the new guy who smells like French onion soup is not your favorite person on staff," Oliver says. "That's no reason to flee him every time he asks you for help on an assignment." Nor should you be spreading gossip about him, Haefner says.
It's best to act friendly toward everyone, Oliver explains: "You will come across as more of a team player and show you have management aptitude."
And according to Haefner, nearly half of the employers CareerBuilder surveyed say they would think twice before moving up the ranks an employee who participates in office gossip.
"Take care that any criticism you make about someone's performance is deemed to be constructive, measured, and deserved," Oliver suggests. Not keeping the discourse civil could cost you your job.
According to employee rights nonprofit Workplace Fairness, 29 states have "smoker protection laws" that make it illegal to discriminate against an employee for the use of "lawful products outside the workplace," or for smoking in particular. In the states that do not have these laws, however, employers are free to fire smokers, even if their tobacco use is solely outside the workplace.
Randall suggests not smoking at the least during work hours, especially when your job is client-facing.
"There is a line between curiosity and nosiness, which you don't want to cross," Oliver says. Curiosity, she explains, is when you ask who the new hire is. Nosiness, on the other hand, is when you rifle through your boss's files to see how much the woman three cubicles down earns.
18. Raiding the supply closet
Taking home a yellow pad of paper and a few pens if you're going to be working from home all weekend is acceptable behavior. But when you raid the supply closet and stash pads of paper, flash drives, notebooks, and folders, you're essentially stealing money from the company, Oliver says.
"Ask yourself if you are really using it for work. If not, leave it be," she says.
The same rule applies for using the phones to make long distance personal calls and using the Xerox machine to make copies of your great American novel.