Agreed that your relationship with your boss and your tone should dictate what’s appropriate. Saying that, I can’t imagine a situation where you say “'sup duuuude?” in your best surfer voice. Even casual professional relationships have their limits.
It depends on context and who my boss is. Mine’s American, so, answering his call goes like this: “Hey, MyBoss, what’s up?” if I walked out a meeting, to, “Hey, MyBoss, what can I do for you, sir?” if I’m not in a hurry. I should note that “sir” is very casual, and is a very different type of “sir” than I would use if pulled over by a cop.
Since I have Chinese working for me, it takes a lot to get them to not be so damned reverent all the time. Sheesh.
I wouldn’t answer the phone that way with my current boss or any boss I’ve ever had, or in fact any of my co-workers. It sounds a little too much like “I’m busy, what do you want?”
Yes, it is unprofessional, but that doesn’t mean it’s a wrong or a problem. That’s what depends on your boss. If she’s the type who wants you to be professional to her, then, more likely than not, she won’t like it.
Not a problem where I work. I’m sufficiently casual for that with my boss, also my boss’s boss and my boss’s boss’s boss. However I would not be that casual with my boss’s boss’s boss’s boss or his boss ( at the top of the food chain ). Just depends on where the comfortably casual relationship ends and the slightly more formal begins.
Depends on your office culture and your relationship with your boss.
My boss: “What’s up?” would be ok.
HER boss: “Hey there, (name)”
Anyone higher: “(Name of my office), this is PandaBear”