What not to do in a promotion interview?

In a promotion interview, don't complain about your current role, take credit for work you didn't do, or behave too casually. You won't win any points for complaining about or badmouthing your boss, coworkers, or responsibilities, so make sure you're speaking positively about your current situation.

You also should be careful to not embellish the truth about your responsibilities and accomplishments -- the interviewers easily check your facts, and it won't go well for you if they find you weren't being truthful. Finally, just because you work at the company or know your interviewer doesn't mean you can be casual or unprofessional. Treat your promotion interview with the same gravity and respect that you would any other interview.