The first things you should do if you're thinking about firing an employee are a) consult human resources and b) get legal advice. You never want to terminate someone's employment on a whim, just because you're angry or because they made one mistake. 

That's according to Michael Kerr, an international business speaker and author of "The Humor Advantage." We asked Kerr and Lynn Taylor, a national workplace expert and the author of "Tame Your Terrible Office Tyrant: How to Manage Childish Boss Behavior and Thrive in Your Job," to tell us about the types of employees who shouldn't be tolerated at any organization, and why. 

Read on for the full list and see if you recognize any of these employee types on your team. 

The employee who's breached company policy 

When an employee acts in a way that obviously violates written company policy, it's time to let them go, Taylor said. 

That behavior depends on what's in your company policy, but likely includes sharing proprietary information, engaging in discriminatory practices, bullying, or sexual harassment. 

The unreliable employee

This is the employee who consistently misses deadlines, and violates their manager's trust, Kerr said. 

The mutinous employee

If an employee overtly tries to subvert senior management by rallying other employees, Kerr said, that's definitely grounds for dismissal.

The grossly incompetent employee

The definition of "gross incompetence" varies based on the role the employee fills. So you'll have to use your judgment, Kerr said. 

Note that this description doesn't refer to a one-time mistake or an error with good intentions — it's about a pattern of behavior that suggests they're not a good match for the job. 

If there is a performance issue, Kerr recommends asking yourself whether the employee has acknowledged the problem and whether they're trying to improve. If the answer is "no" to one or both questions, there could be trouble ahead. 

The employee who's repeatedly and mysteriously absent

It goes back to not being able to trust your employee, Kerr said. If you can't even rely on them to show up to work, you probably can't rely on them to submit solid work. 

The antagonistic employee

This is the employee who likes to spark — and win — arguments for no apparent reason. For example, Taylor said, they might wander over to a colleague's desk and start a political conversation, just to ruffle feathers. 

Or, Taylor added, they might constantly play devil's advocate, using phrases such as "But what if..." and "That would never work because..." in meetings. In other words, they quickly "sap morale." 

The stubborn employee

The stubborn employee makes it difficult for their boss and coworkers to get things done, Taylor said. Often, they think they know better than their boss and get defensive. In general, they're considered a poor team player. 

The whiny employee

Whiny employees complain to the point that their manager almost feels bad about giving them assignments, Taylor said. She added that even if the whiny employee is skilled, it might be worth letting them go just to save yourself the constant aggravation. 

(Plus, real-estate mogul Barbara Corcoran said she always fired complainers at The Corcoran Group.) 

The gossip-monger employee

Badmouthing coworkers shouldn't be tolerated, Taylor said. "Nine times out of 10, the gossip they spread will come back to them." 

The employee who's not accountable for their mistakes

If an employee consistently denies responsibility for their missteps — or worse, blames them on others — it's time to think about letting them go, Taylor said. 

As a manager, you want to see that your employee has learned from their mistakes. If they don't, that's a bad sign.