You know it's coming – the rest of the job interview has been going well, you've managed to strike up a good rapport, you've discussed the company's expectations and what this position entails, but you feel it looming. It only makes sense for them to ask: "Why do you want to leave your current job?"
The truth is that you want to leave your current job because you hate it! It's horrible! Your coworkers are catty, backstabbing gossips. Your boss is downright disrespectful to you in front of your colleagues. You've been passed over for a promotion in favor of some young kid who doesn't know what he's doing. You do the same thing every day and it's less interesting than watching paint dry. You work long hours and stay up late thinking about work but you haven't gotten a raise in three years.
But, of course, you can't say any of that on an interview. So what do you say?
You don't have to pretend your current company is the best place to work, but you also can't go negative.
It's usually wise to steer the conversation toward what you hope to do in your next position instead of what's happening in your current job. The idea is to focus on the fact that you're ready for the next step in your career. This is the perfect opportunity to discuss how what you've already done has prepared you to take on this new role and new challenges, while not sounding as if you're expecting the new job to be a huge learning opportunity.
Use any relevant experience you have as a springboard - you may want to say something along the lines of, "I've had some really great experiences at XYZ Corp., including the chance to oversee a few company-wide initiatives, and I'm excited to use my strong leadership and organizational skills to take on more project management responsibilities. You mentioned wanting to introduce new automations, and not only have I worked with this software extensively, I also helped XYZ Corp. transition from its manual processes to using new technologies."
You could also talk about issues that aren't your company's fault and wouldn't be concerns with the new employer. Perhaps you would save yourself 20 minutes commuting each way, and you could tell the interviewer, "Part of why I'm looking to leave is because I want to find a position that's closer to home." Or you could discuss company size, "After working for a large company for several years, I'd like to move into a smaller company that's more specialized."
If you work for a company that's recently had a high-profile crisis or is known within the industry for experiencing heavy turnover, you could touch on it in your response. But this is dangerous territory and requires a good sense of diplomacy. Your answer might sound more like, "With multiple restructurings in the past two years, some projects have fallen through the cracks, and I'm looking for an opportunity to work with a company focused on follow-through and achieving large-scale goals."
Whatever you say, remember that the goal is to move forward and your answer shouldn't give the prospective employer any reason to doubt your ability to fit in with their company. And once you get the new job, some of the worst things about your current position will just be funny stories about this terrible job you used to have.