Mistakes to avoid during a job interview It's easy to make a mistake when you are at a job interview. In fact, sometimes you don't even know you're making a mistake. I've spoken to several job seekers who didn't realize that it wasn't acceptable to be in an interview with the cell phone on and the worst part answering it. I've also spoken to applicants who have erred on the side of being too late for a job interview or dressing too casually or even too over-dressed for the job or the company. They thought they were doing the right thing. Instead, they ended up not making the best impression. Some of the interview mistakes made most frequently should be obvious, others aren't as clear, especially if you haven't interviewed much or in a while. Here are the most common interview mistakes to review so you can avoid making them. Enjoy the lesson!