It depends on what package you're on. If you're on the basic package, then I'm not sure you get access by default (you'd need to check that with BT customer services). Although if you're providing a BT Openzone hotspot I don't see why you shouldn't really (in my opinion).
If you're on the advance package then you get 250 mins per month (just call BT business customer help and they can sort out an account and associate all the free minutes to it).
