Filling a prescription appears to be a simple process. However, collecting a prescription from the doctor's office and ensuring that it gets to the pharmacy without being damaged or lost is sometimes a dangerous task. This can be harmful to a patient's health. Insurance companies also play a role because they have varying policies on when a script can be renewed. In the case of the pharmacy, the day count begins on the day you pick it up, even if it is two days before the due date.