can i use 3G iphone without a data plan?

[Barbara]

I heard that I can't use an iPhone without the data plan. The SIM card will not work. Is that true? If I buy an used iPhone can i use the phone without the data plan, just connecting through wifi (wireless)?

[dontaskwhy]

If you use an iPhone w/ At&t, you are required to have the $30 iPhone unlimited data feature. If you manage to activate or remove the feature, the Terms & Conditions of Service require it and At&t can add the missing feature at will even if you don't want it.

However, if you don't want to use the phone to make and receive calls (no voice plan), you can just use wifi for data only. Essentially the device would be an iPod.