1. Thinking it's not a real interview. Some job seekers treat phone interviews as if they're a casual get-to-know-you chat. They rarely are. Phone interviews are what employers use to preliminarily narrow down their pool of candidates and decide who will move forward in the process. If you want to get the chance to talk to this employer again, you need to excel. Speaking of which …
2. Not preparing. Just like with an in-person interview, you should study the job description, research the company, and practice your answers to likely questions. Yes, some interviews are short screens, but some ask in-depth questions about your experience, even getting into trickier behavioral interview questions. Don't wing it.
3. Not finding somewhere quiet to take the call. It might sound like obvious advice, but plenty of candidates take calls in public spaces with noise from a crowd, or at home with barking dogs or interruptions from kids. Find a quiet, private space where you won't be interrupted—especially by coworkers, if you're currently employed!
4. Not using a reliable phone connection. The conventional wisdom used to be that you should never use a cell phone for a phone interview. But these days, when many people don't even have access to a landline, this isn't always practical. What's key is using a phone that will give you good reception and sound clarity and that won't drop the call.
5. Not paying special attention to your tone of voice. In a face-to-face interview, eye contact, facial expressions, and body language might all convey signals about your interest and enthusiasm. But in a phone interview, since the interviewer can't see you, tone of voice becomes especially important. Make sure that you sound engaged, upbeat, and friendly.
6. Not being ready for typical screening questions, such as your questions about your availability or your salary expectations. Phone interviews are often used to ferret out basic incompatibilities quickly, such as learning that you can't start for three months when the employer needs someone who's available immediately, or revealing that your salary expectations are much higher than the employer's intended pay range for the position.
7. Not having your application materials handy. The interviewer will have your resume in front of her, and you should too. Don't risk blanking if she asks how long you were at job X or what your title was at job Y.
8. Allowing yourself to get distracted. Quit your email program, turn off instant-messaging, and log out of any other programs on your computer that might distract you. If an email comes in while you're talking and you start even partially processing it, you will take your full attention off the conversation and will sound distracted. This is not the time to multitask.
Alison Green writes the popular Ask a Manager blog, where she dispenses advice on career, job search, and management issues. She's also the co-author of Managing to Change the World: The Nonprofit Manager's Guide to Getting Results, and former chief of staff of a successful nonprofit organization, where she oversaw day-to-day staff management, hiring, firing, and employee development.