When a job candidate has a less-than-perfect interview, it doesn't necessarily mean you're at a dead end or that he’s wrong for the position. But there are some key warning signs you shouldn’t ignore during the recruitment process. The next time you interview a potential employee, watch out for these seven interview red flags:

1. Fumbling the basics

Here's one of the top interview red flags: When job candidates show up late for an interview, it usually means one of two things: They don’t value the job opportunity enough to be on time, or they aren’t good at planning ahead. And although you can’t judge a book by its cover, attire and grooming should be appropriate for an accounting or finance job interview. If it’s not, you might be dealing with someone who lacks professionalism or good judgment.

2. Jekyll and Hyde

This is an interview red flag that might be hard to spot. Some candidates show the interviewer one personality while presenting another to everyone else. Ask your receptionist and other office personnel about their experiences with the candidate. If interviewees are polite to you but rude or impatient with your staff, they'll likely giving you some insight into how they might behave around your workplace if you hire them.

3. Lack of attention

You can tell whether a candidate is really interested and engaged by body language, eye contact and overall etiquette during the interview. Does the candidate look at the clock or check his smartphone during the interview? Does the interviewee look bored with your questions? Both things are strong interview red flags that the job might not be a good fit.

4. No pre-interview research

At some point during the interview, you’ll probably ask a few company-specific interview questions, like "What attracted you to this firm?" If the interviewee stumbles or gives you a generic answer, it may be a sign that he didn’t research your company before the interview — perhaps because he’s not organized enough to prepare well, or because the position isn’t a high priority.

5. No questions

Is the interviewee asking informed questions about your company — or only responding to what you ask? If it’s the latter, it could be an interview red flag that the candidate isn’t eager to work for your company specifically, but just needs a regular paycheck.

6. Trash talk

If candidates readily badmouth former employers and coworkers, you can bet on them doing the same while working for you. Questioning and critical thinking are good traits, but you don’t want an employee who doesn’t show respect for his colleagues, which may indicate an inability to work with a team or take direction.

7. No follow-up

It’s professional courtesy to send an thank-you note or email to a hiring manager after an interview. When candidates don’t follow up in this fashion, it can indicate a lack of professionalism — or a lack of interest in the job.

Not all interview red flags are easy to spot. But they're worth looking for, if you want to avoid the costs of a bad hire.

See the following posts to learn more about how to conduct interviews, and contact Robert Half to find top talent in your area.