Can a normal SIM be modified to work as a nano-SIM?

Question

I just puchased an iPhone5 and want to use my current SIM from my existing phone. Is there a way to convert my existing SIM to nano-SIM?

Answer 1

No. You could cut it to the same dimensions, but the risk to damage the chip is high. Additionally the nano sim is slightly thinner, so it still wouldn't be a good fit.

I suggest you exchange your sim card with your operator. Note that there exist adapters to fit a nano sim in a larger form factor though.

Answer 2

The downsides of converting your SIM are:

• You no longer have a SIM to activate your old iOS phone (assuming it's an iPhone).
• If you mess up the cut, you still need to go get a new SIM (perhaps two)
• If your cut isn't precise, the SIM could wiggle loose later from the carrier since the nano-SIM carrier is designed for a thinner card and very precise dimensions.
• Your carrier might expect newer SIM in the devices and your service could be impacted (very low chance - but I've seen it happen with AT&T and older Cingular, other SIM's that eventually lose support if you don't get their newer numbered SIM cards).

The upside is you might skip a trip or a call to your carrier and if you are good at cutting, you can shave down an existing card if you really want that thrill of DIY.

Engadget has a nice picture of the carriers you could use to place a nano-SIM into a phone that expects a micro-SIM or SIM. Here are the micro-SIM and nano-SIM compared to some common coins for a reference to how small scale these are physically.

^{Photo from Engadget}
The real issue is if your contacts on your SIM (or micro-SIM) are placed in the correct places for the iPhone 5. Here is a picture showing that some micro-SIM have larger/different contact points than a nano-SIM.

^{Photo from Today's iPhone}

Answer 3

I've read a number of positive reports on DIY resizes. Apparently Apple allowed enough slack in the nano-SIM slot that the thicknesses is not an issue. It does require careful cutting and if you screw it up you'll need a new SIM. You can find templates and instructions on the Internet. I have not seen any punches yet for nano-SIM's.

As suggested, if possible, it's better to get a replacement nano-SIM if your carrier offers it.