I am currently subscribed to a business plan. If we come near to exceeding the transaction limit, per these forums it seems that an email warning is provided. If the plan is then upgraded to a plan with a higher transaction limit, does the higher transaction limit immediately take effect? Can this be done at any point during your billing cycle? or the change can only be made at the end of the billing cycle effective the following month?
Also, if you change your plan in the middle of your billing period, is the cost of the plan pro-rated up or down per the cost of the new plan?