When you reserve a public IP, we take care that the IP cannot be used by other users, so you can use it freely.
The price stated at the Reserve IP Address page is the price for 1 month (until the end of the current month). On the 1st of the following month a fee will be charged again. Your credit of 1 month fee will be immediately held. You will be charged in full until the end of the month even if you only create it for a few minutes or hours and delete it.