Yes, you can! On ISP proxies, you can renew the same IP indefinitely. You can also renew it before the expiration date
After your ISP proxy has expired, it isn't guaranteed that you'll be able to extend it. To avoid losing your IP, it is recommended to extend it at least one day before the expiration date
If the IP you're trying to renew isn't available, a new IP will be assigned to you
If you purchased a 30-day plan, the renewal will also be for 30 days. Currently, it is not possible to switch to a 90-day term for an ISP proxy that was originally purchased for 30 days, or vice versa