Whether you're interviewing for a new position or giving notice to your boss, chances are you'll be asked what's behind your decision. A potential employer wants to know why you're no longer interested in your current job, while your current employer is curious about what you find unsatisfactory enough to prompt you to leave. How you answer depends on what you're hoping to achieve with your response.

During an Interview

If you’re still employed while you're conducting a job search, hiring managers will ask you why you’re seeking a new position. The interviewer wants to know if you’re dissatisfied with your current position or your pay scale, or if you have problems with managers or colleagues. They ask this question to gauge whether you'll be a good fit for the organization and to look for red flags that indicate you're potentially a problem employee who can't get along with others. Use the opportunity to stress what you find attractive about the new position. “I’ve outgrown my current role and I'm looking for new challenges. I have great respect for the work this company does and I’d like to be part of its future.”

During a Resignation

When you give your boss notice, he's likely to ask why you're leaving and where you're going. If you're looking to give a polite response, simply state you're interested in pursuing new opportunities or challenges, and avoid saying you're underpaid, feel underutilized or that you don't like your co-workers. “As much as I’ve appreciated the opportunity to work with you and my colleagues and this fine organization, it's time to challenge myself and look for new ways to expand my professional horizons.”

During an Exit Interview

When you leave a company, human resources traditionally conducts an exit interview. You’ll be asked why you’re leaving and what you liked and didn't like about the company during your tenure. If there are specific reasons you're leaving that you’re compelled to share, the exit interview is the place to reveal them. Even if the reasons are negative, you can still be polite in expressing yourself. “Unfortunately, the pay rate for this organization isn't in line with industry standards, and I just couldn't afford to work here any longer,” for instance.

Talking to Others

Colleagues, business associates and customers may ask you why you’re leaving your position. Maintain a professional demeanor and don't say anything negative about your employer that could follow you in the future. Come up with a pat response to all questions and don't allow yourself to be goaded into providing any additional information. For example, “It's time for me to make a strategic career move,” or, “I have an opportunity for significant professional development.”