Originally Posted by
mikeo007 I don't believe there is a way to put a hard limit on data usage from the phone itself. Your best bet would be to talk to his cell provider. Most will send you a text message when you approach 100% of your data usage. They may also be willing to put a hard cap on data usage from their end.
ATT will send you a notification, but with a 300mb plan, that notification is often too late to prevent the overage. ATT will also, apparently, sell you a $5/month plan to allow you to set a hard cap, but wont just cap it for free from what I can see.