How To: Use an iPhone with AT&T without having a data plan
There’s a way around having the mandatory data plan with a smartphone on AT&T…
Here’s a list of phones AT&T does not “mandate” the data plan on that are actually smart phones.
Also, some people have had luck doing this to make sure the plan never gets added:
1) Put Feature (dumb) phone on account, and put SIM in feature phone
2) Call AT&T and have them put data block on this account
3) Wait a day or so and put SIM back in iPhone
4) Most folks that do this never get the data plan added to their account.
5) If you need to call AT&T back, simply put the SIM back into the feature (dumb) phone before calling them, and turn it on so it registers.
I’ve done the above for about six months and it worked fine with an iPhone 4. The key is to do the steps in that order. Text messages still DO work, but MMS ones will not (they need data). The phone will not have a “E/3G/4G” indicator on it at all with data removed. You will simply see bars and “AT&T” next to it.