With BT Mobile you can manage how much you spend each month by setting a spend cap for anything outside your plan.
Here are some answers to help you
How can I manage my BT Mobile spend?
What if I go over my BT Mobile data or call allowance?
If you go over your data and call allowance, maybe consider upgrading your plan or ordering an add-on to tide you over.
BT Mobile: How much data have I used?
Go back to: What can we help with?