Last Updated: March 25, 2014
Question: Can I Keep Unlimited Data with iPhone Tethering?
I'm excited that AT&T has allowed iPhone tethering (finally!), but I know they also recently changed their data plans. I've got the original unlimited iPhone data plan, which seems perfect for tethering, but can I keep the unlimited plan if I have tethering?
An unlimited data plan would be the perfect match for the iPhone's Personal Hotspot feature, wouldn't it? While it's perfect from the user's perspective, it's not AT&T perfect world. That's why, when they changed the data plans, they set terms for tethering.
IPhone tethering cannot be used with an unlimited iPhone data plan. Instead, tethering requires AT&T's 5GB data plan or higher, which currently costs $50/month, with no additional charges for tethering. If you use more than 5GB of total data in a month, overages run $10 for 1GB.
All cellular data - whether on the phone or via Personal Hotspot - combines to count against your monthly allotment. For users who don't tether, this should be OK, but with tethering, you may need to keep an eye on your monthly data use.
UPDATE March 2014: While the original Q&A was specifically about AT&T data plans, it applies to virtually all carriers in one form or another. No carrier that I'm aware of offers unlimited data for Personal Hotspot at the highest speed. Some carriers charge for overages, while others throttle your speed (i.e., reduce the speed of the connection after a certain amount of data used each month). But either way, there will be some limits based on your use.