Introduction: How to Turn Your Cellphone Into a Credit/debit Card

Easy to do mod for an extra credit/debit card with RFID chip (i.e. Paypass).

Using this method, you will be able to locate and extract the RFID chip in your spare
Paypass-capable card and place it in your cellphone. This will allow you to present your cellphone at Paypass terminals (movie theaters, McDonalds, etc..) and pay using the RFID chip.

Step 1: Get Your Materials

Items needed:
- Spare credit/debit card with embedded RFID chip (if go to your bank and request a new card they will typically send you a new card w/ the same number and info).
- Scissors
- Cellphone
- Magic marker/ Sharpie

Step 2: Find the Chip

In this instructable, I am using an old, deactivated debit card. I found the RFID chip in a previous card by cutting into it randomly.
I DO NOT recommend this method if you don't know where the chip is, as you could obviously damage the chip and make it unusable.
I do not know if all cards are setup with the RFID in the same location, but if they are, my guidelines will give you a good idea where to start.

If not, I was able to see the impression of the chip on the back of the card when I looked at it from an angle in a well lit room (it appeared as a small square impression only a few millimeters across).

Make sure to mark out a guideline to cut along that goes from the bottom of the magnetic strip to the top of the imprinted card numbers. This will yield a decent size chunk of the card with the RFID in the center.

Step 3: Cut Out the Chip

Be very careful when cutting out the chip.

Less is more!

The initial size may be fine for many people and is small enough to be placed in many cellphones or anything else you can think of. But if you're like me and have an env2 or similarly compact phone you need it a little bit smaller.

Going any further than the initial cutout comes with the risk of damaging the chip.
Consider yourself warned.

When cutting close to the chip you may break the seal around it and the sides may begin to separate.
You DO NOT want this to happen as you want the plastic for insulation around the chip.

Step 4: Place the Chip in Your Phone

This last step is pretty self-explanatory.
However, there are two possible ways to go about it.

1. I've found that the easiest way of placing the chip inside the phone is by placing it inside the battery cover.
In the case of my env2 and other compact cellphones, there is very little wiggle room available to place anything extra in the battery compartment. For my phone, I would trim the card more than shown in order to create a lower profile inside the battery compartment.
For others the chip in the size I show here may be more than adequate.

2. This second option is for those are not utilizing their microSD card slots (if available).The plastic around the RFID can usually be trimmed enough so that it is able to fit into a microSD card slot.
I only offer this option as an alternative for those willing and able to do so. Just make sure you can remove the chip from the slot and that there is no way to cause a short while the chip is in the slot.

Step 5: Success


You now have a fully operational RFID-embedded cellphone.

Oh, and please let me know what you think as this is my first instructable.

P.S. before I forget, I did not come up with this completely on my own. I had seen something similar almost a year ago online. Try as I might I can't seem to find the site anymore. I just want to give credit for the inspiration to the author of that webpage, whoever they may be.