iPhone 4 Data Plan Works on iPad 3G (No Jailbreak!)
Ever wondered if you could swap out the micro-SIM card in your iPhone 4 to get free data from AT&T on the iPad 3G? Well stop wondering. Turns out a simple change to APN settings on the iPad makes it possible to use the iPhone 4 data plan on Apple's tablet. No jailbreaking or SIM card modifications required.
As the helpful folks over at TUAW explain, the procedure is quite simple but does involve many small parts. Carefully use a SIM removal tool or paper clip to open the SIM trays on your iPhone 4 and iPad 3G. Don't mix up the trays and keep track of which card came from which device! When the iPhone 4 micro-SIM is safely inside the iPad 3G, all you need to do is make a change to the APN settings on the iPad.
Under Settings -> Cellular Data -> APN Settings enter the following information:
Now the iPad 3G will function normally using the iPhone 4 data plan. If you've owned an iPhone in the past you probably still have unlimited data. AT&T has recently moved to tiered, limited data plans on its mobile devices.
Although using the iPhone 4 data plan on the iPad 3G is a simple procedure, AT&T does not condone the practice and you may get into trouble with the terms of your data contract. Swapping SIM cards between devices is not something AT&T or Apple want to encourage.
Data plans on the iPad and iPhone 4 for new subscribers run $25 per month for 2 GB or $15 per month for 200 MB of usage. Users of older iPhones have a different sized SIM card inside their devices, so this procedure will not work if you want to swap an iPhone 3GS or older card into the iPad.