A hiring employer has an obligation to make attempts to use every legally available means to determine an employee's fitness for a job. That is the catch. As a supervisor or manager you may find yourself wearing both of these hats. Clearly, beyond the legal requirements, reference checking is an important function of finding the best person for the job you are filling. That depends on the position being filled and how critical it is to the smoothly running operation of your company.
Many employers call references after interviews have been conducted.
This is not necessarily the best procedure. Some employers find that by calling references before scheduling the interview, they are able to screen out undesirable candidates more effectively, thus saving themselves the time they would have spent in an interview. In addition, checking references before the interview can provide you with additional areas to explore during the interview and let you formulate pertinent questions in advance. You should always seek permission from the job applicant before checking references. A good method of doing this is to include a statement on the application form requesting the applicant's permission to contact any individuals mentioned on the form.