[southin]

My Canadian iP4 is unlocked. I'd like to have internet access in the States, where I go often for a couple of days at a time. AT&T doesn't sell pay-as-you-go data plans for phones, but they do, of course, sell them for iPads, which take the same size microSIM. Can I plop an iPad microSIM into my iP4 and buy (and use) one of the two AT&T data-only plans? (My current iPad in just wifi, so I can't use it to buy a data plan, but it's presumably easy to buy an AT&T microSIM and say it's for an iPad.)

[subego]

The US Apple store says no.

iPad - iPad WiFi - iPad WiFi + 3G - Apple Store (U.S.)

Edit: Canadian one too.

iPad - iPad WiFi - iPad WiFi + 3G - Apple Store (Canada)

[southin]

Yes, but... Those pages also say that the iPhone SIM will not fit into the iPad, which is clearly incorrect (in the case of the iP4). They seem to have been written before the iP4 was introduced, and not revised thereafter. So I don't think that's a dispositive answer to my question, which, in any case, had to do with using an iPad SIM in an iPhone 4, not vice-versa.

[subego]

Canadian store says no.

iPhone 4 & iPhone 3GS - Apple Store (Canada)

The US store is silent, but I'm noticing a trend.

[amazing]

just try searching for "using ipad microsim in iphone 4" into google--you'll see all the details you need to know.

The short answer is the ipad microsim isn't provisioned for voice calls.
iPad and iPhone 4G Micro-SIM Cards (In)Compatible? | PadGadget

[Phileas]

Given that the iPad is not a phone, this shouldn't come as much of a surprise.

[subego]

Originally Posted by amazing 

just try searching for "using ipad microsim in iphone 4" into google--you'll see all the details you need to know.

The short answer is the ipad microsim isn't provisioned for voice calls.
iPad and iPhone 4G Micro-SIM Cards (In)Compatible? | PadGadget

If I'm understanding correctly, that doesn't answer the question. southin just wants to use the iPhone for data.

[amazing]

ah my apologies: thought it needed voice as well.

sounds like it will work for data.

[Wiskedjak]

it'll work for data. you just need to change the phones apn.
Unlockit - APN Changer for your iPhone

the tricky park is getting the sim activated. you might need a 3G iPad for that.

and then, you just need a Skype number.

[subego]

Nifty!

Glad to have been proven wrong and my apologies for the bad info.

[Wiskedjak]

Indeed. Next month I'm going to try this using just data on my 3G. I'll use Skype for all of my outgoing calls and Google Voice for all my incoming.

[The Godfather]

How would you use google voice with no Cellular phone service?

[southin]

Does the fact that my iP4 is unlocked (it was bought that way from Apple) still mean that the APN needs to be changed? (Pardon my ignorance, but I have no idea what an APN is or does; I was rather hoping I could just plop in to the iPad microSIM and order service just as I would with the iPad. Naive or what?)

[Wiskedjak]

Originally Posted by The Godfather 

How would you use google voice with no Cellular phone service?

for voice mail only. I don't spend much time on the phone, and mostly use voice mail to screen incoming calls.

[subego]

@southin

It looks like it's close to that simple.

That website will actually change the APN (which is the info the phone needs to "handshake" with the cellular data network) for you. It's a webapp. When you're done, you delete the profile it creates and you're back to normal.

It doesn't say, but I presume you want to change the APN right before you do the swap.

As for getting the iPad sim activated... That's another story. I wouldn't know how to do that outside of having a 3G iPad.

[Wiskedjak]

if I recall, for a factory unlocked phone, he may not need to go to the APN changer website. I think for factory unlocked iPhones, there is an editable APN field in the Cellular Data settings.