Fair Usage Policy (FUP) throttles the service headline data rate to 64kbps up and down when you reach the data limit. You can purchase GByte Boosters to continue with services.
Volume Based Billing (VBB) does not change your headline data rate and service is never suspended. You will be charged for any excess GByte data usage the following month automatically.
You always have access to the portal page at http://portal.avantiplc.com to see how much you have used.