You know someone at iPhone Life had try making their own micro SIM card so I took the plunge and decided to sacrifice a T-Mobile card I had to give it a try in my iPad 3G. You can certainly do this with the iPhone, but you’re going to have to jailbreak and unlock it if you want to use a carrier other than AT&T. The iPad 3G comes unlocked, except in Japan.
It’s a relatively simple, though delicate operation and I suggest doing a test run with an old SIM card if you have one so you can get a “feel” for how hard the plastic in a SIM card is. So with that in mind lets proceed.
You will need: a full size SIM card, a micro SIM card or take the measurements off my micro SIM here, a solid and sharp pair of scissors, a mechanical pencil with .05 lead or a very sharp pencil (for tracing the outline of a micro SIM over your full size SIM) a very steady hand and a sharp eye.
Once you have your outline of a micro SIM on your full size SIM, it’s time to start cutting. I started by cutting the sides that were the closest to the gold contact point (in the photo and video the two sides abutting the ruler), that way I had a bit more card to hold on to when making those fine cuts. Also notice on the right side of the micro SIM, you should have 3mm of excess plastic.
You’ll notice that I have a bit of bevel on my cuts; it’s really hard to cut a straight line, so take your time and make sure you can see where you’re cutting. Once you have cut your SIM down to size, then you’ll need to cut the corner off the top right, this is where having traced a card can help – so you get the angle right. You will probably have to cut just a smidge off each of the three remaining corners to round them so they fit in the tray too.
At this point you’re ready to see if it fits in your micro SIM card tray, you’ll see if you have to trim any more, be careful not to over trim the card.
Now comes the moment of truth. Put your new micro SIM in the card tray (make sure it’s indeed seated and flush, and insert it into your iPad 3G or iPhone 4.
Go into Settings and check to make sure you have Cellular Data turned on, and wait for it to find a signal – it should go without saying, but make certain you’re in an area which has coverage by the carrier.
So why would anyone cut a perfectly good T-Mobile SIM card down to a micro SIM? I did it firstly to prove to myself I could do it, however the other reason is that I want to be able to have a choice of data carriers for my iPad. True, with T-Mobile you are stuck with slower EDGE service since their 3G is on the 1700Mhz spectrum (AT&T runs on the more common 1900Mhz), but for me it is about choice. I also want to know that when I travel abroad, I can potentially purchase a prepaid data plan from another carrier and if they don’t offer micro SIM, I can cut it down to size.
I hope to put that theory to the test next Summer when I go back to Budapest Hungary and use Whistle (free) to make VoiP calls over GPRS or hopefully 3G.