Workplace illnesses cost companies millions of dollars each year. Many supervisors now require employees to bring in doctors notes either confirming their illnesses or stating the employees are healthy enough to return to work.
Employers often have several reasons for requiring doctors' notes. At times, they want to ensure that a worker was genuinely ill, and not faking poor health simply to get out of work. Other times, they need confirmation from a professional that the employee is free of contagious diseases.
An employer can, in fact, check the validity of a doctor's note, but how and when he does this is up to his discretion. He can call the doctor's phone number, if it is provided, or perform an Internet search on the physician to determine if he exists.
Determine the policy of your company regarding sick notes and paid time off before you become ill. Certain organizations do not require a doctor's slip if you have only been out for a day or two.