In the business world, the strength of your reputation carries as much weight as your skills, work experience and other qualifications. If a former employer implies that you’re a subpar employee, you could find yourself locked out of the industry. Unless a prospective employer explicitly tells you, it is highly likely you will never hear about it. If you want proof, you’ll have to do a little sleuthing.

Read Between the Lines

Pay close attention to how prospective employers treat you before and after they meet with you. If they’re enthusiastic during the interview but inexplicably turn cool after they talk to your references, your former boss might be the reason behind their change of heart. You can also ask employers what your boss said about you and if that’s the reason you didn’t get the job. If that didn’t play a role, they’ll likely say so. If they’re vague, however, that’s a strong clue they don’t want to reveal what your employer's comments.

Remove Your Boss as a Reference

If you repeatedly lose out on jobs after prospective employers check your references, stop giving out your previous employer’s name. If things improve, it’s possible your supervisor was to blame. If you want references from your last company, enlist colleagues or other supervisors you trust. If they wonder why you want to use them instead of your former boss, tell them you think they’re more familiar with your strengths as an employee.

Check Your References

One of the surest ways to discover if you’ve been blacklisted is to check your own references. You can hire third-party services who will not only call your previous employer but create a detailed transcript that notes tone of voice and other clues. Even if your boss doesn’t outright say you’re a bad employee, he could subtly suggest that you’re not a good candidate. If you don’t want to hire a service, ask a friend or family member to call and record the conversation so you can hear what is being told to employers.

Talk to Your Boss

Even if you parted on bad terms, consider talking to your previous boss. If you don’t want to accuse him of compromising your job search, simply ask if you can use him as a positive reference. Many employers who won't recommend you will tell you, especially if they think they have a strong reason. If your boss won’t admit his behavior, tell him you’re concerned that what he’s saying is hindering your ability to find a new position.