
Originally Posted by
just4kix
Third answer is correct. If a plan change happens on, say 10th, then:
From 1st to 9th, billing will be as per old plan. Usage limit will be as per old plan and apportioned. For example, if the plan was Home 500 C (usage = 1.5 GB), then for 1st to 9th, the usage limit will be apportioned to 460.8 MB (assuming 30 days in the month; even less for 31 day months).
If the usage limit from 1st to 9th exceeds 460.8 MB, usage charge will apply at 0.80p per MB.
For the rest of the month, if the plan is changed to UL750+, then of course there is no usage limit. But overusage during first nine days will still apply.