I was reading the usual tech sites and came across
over at TUAW. It was about using an O2 SIM card (not the U.K. phone company, the U.S.A. one) in the
iPhone 4. All you had to do was activate the SIM, then cut it down to fit into the iPhone's micro
SIM card tray and it just worked.
Perhaps you received an iPhone 4 as a gift and don't want to sign a two year contract with AT&T, or maybe you just aren't much of a talker but still like smartphones, or maybe you don't live in an area serviced by AT&T. Whatever your situation is, you have other options. If you use an AT&T GoPhone SIM you can even have a 3G data plan with your pre-paid minutes (which can last up to a year before expiring). You can also get a data plan using an O2 SIM (now called H2O). However the service plan requires a $49.99 voice plan and only includes 30MB of data.
If you decide to unlock your iPhone then you can use Simple Mobile or T-Mobile. You can get data with both of these companies as well. Simple Mobile resells access to T-Mobile's network so you will not receive 3G service using an iPhone. You can see my T-Mobile tutorial here. I purchased a Simple Mobile SIM from their website here. They also have a network of resellers in various retail stores so check their site. You can see my Simple Mobile tutorial here. You can get data, tether, use MMS and FaceTime on Simple Mobile and T-Mobile. Simple Mobile will require you to pay every month: you can't keep your minutes over a long period of time like you can with an AT&T GoPhone, H2O or T-Mobile pre-paid accounts.
For the record, my iPhone 4s are properly activated and one still uses the AT&T network. They were purchased in the United States directly from AT&T. I have since canceled service on one of them and I restored it with an inactive AT&T SIM, and inactive Cingular SIM, a newly purchased GoPhone SIM, a newly purchased H2O SIM, a newly purchased Net10 SIM, and a newly purchased O2 SIM and they all activated the iPhone. While you can not use a Net10 SIM in an iPhone for airtime, you can purchase airtime recharge cards for O2 and GoPhones at almost every convenience store or electronics store. You can get data on a GoPhone SIM for $19.99 for 100MB. I have an AT&T GoPhone SIM with working data plan tutorial here.
Note: If you use an AT&T GoPhone (you can buy one of these phones almost anywhere with a SIM and airtime included), make sure you do not activate the SIM with the phone that it came with. Ideally you would activate your iPhone with another active AT&T SIM. If you have to use the GoPhone SIM to activate the iPhone it will be bonded to that iPhone for an unknown period of time (I've read six months).
I purchased an O2 pre-paid SIM card at Best Buy. O2 has recently rebranded themselves as H2O. You can see their old site here, and their new site here. I will not be making a tutorial for H2O/O2 as their data plan is very stingy.
The next step is to cut your SIM down to the size that the iPhone 4 will accept. You can do this one of two ways: cut it by hand using the original iPhone 4 SIM as a template or purchase an automatic SIM cutting tool. I have personally done this both ways. Update: T-Mobile now offers micro SIMs (with a 2 year contract) here.
To cut it by hand take a look at this guide that PlanetBeing (from the iPhone Dev Team) discovered. This method works, but it's nerve wracking cutting the SIM card. My advice is to cut a little at a time. You can always take more material off, but you can't add material back to the SIM.
The iPhone 4 (and the iPad) use a micro SIM card. It's a new thing in the U.S. so it's not in wide
use. Since the iPad and the iPhone 4 were released, a few companies have popped up that sell tools
to automatically cut down full size SIMs into the micro SIM format. Here is
one site (it took 30 days to
arrive), and here
This one took 45 days to arrive from Hong Kong. Both units are identical with the latter having the
Noosy logo on it. They are both very sturdy devices that cut the SIM perfectly. Both come with two
adapters to allow the micro SIM to function as a full size SIM card. However, they do cut the SIM
so well that you can easily place it back into the card it was cut from to use it again as a
There is even a site that takes full size T-Mobile SIM cards and cuts them down for you here. Some also sell adapters to take a micro SIM and place it back into a phone that uses full size SIMs. I have had no luck ordering these adapters from the United Kingdom.
Here are my screen shots after the installation of the H2O and O2 SIMs. Note: Activate the SIM card first (with the instructions that come with the SIM), then it will work in the iPhone. While the packaging claims it works in any unlocked GSM phone, it clearly works on the AT&T network in locked phones as well.
Here are my screen shots after unlocking and installing the Simple Mobile SIM. This SIM will not activate the iPhone, so you'd better have one of the other SIMs I mentioned earlier to do this for you. Otherwise you must hacktivate to use it. Some jailbreaking programs do this automatically.
Here are my screen shots after unlocking and installing a T-Mobile SIM. This SIM will not activate the iPhone, so you'd better have one of the other SIMs I mentioned earlier to do this for you. Otherwise you must hacktivate to use it. Some jailbreaking programs do this automatically.
There is a Wiki that lists (based on country) which pay as you go SIMs are available for your iPhone.