What should I say if I'm asked about my previous employer (if it wasn't a pleasant experience)?

Usually, if someone is applying for a position, the company’s application will request to list all or a portion of the person’s previous jobs that they worked. Sometimes, the application will only require an applicant to reveal and list the employment for the last ten years or so. However, the applicant always needs to include the most recent employment. If the applicant is still working at this place of employment, then sometimes the application will ask if the company can contact the person’s current employment.

This would allow the applicant to not have the company call their employer, but the company may call them later. The previous employer must be stated unless there is a good reason for excluding it like it was a job that did not relate to the industry you are currently applying for.