When we take an application over the telephone, we set a “Start Date” at the beginning of the next month or later.  That gives you time to call and cancel your old insurer, which you will instruct to stop coverage the day before your new policy starts coverage.  We prefer to give at least two weeks between taking the application and the start date of the policy.  That gives plenty of time for the new policy to be approved by the new insurer and time for the old insurer to cancel their policy.  The insured person must call the old insurer and cancel the more expensive plan.  IMPORTANT Never cancel your old insurance policy until you have received official notification that the new policy has been approved.