Instructables

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.
 
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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

Congratulations!

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.
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Carmageddon2 years ago
Guys, look at this picture - I am trying to remove the RFID system from my work tag, so I can put it inside my phone.

Look at how tiny the chip is!
Any idea how to get it out of there intact, so that it works?

I was not really able to find any instructions on this size of chip.

http://img62.imageshack.us/img62/8133/chipd.png
That is VERY small
Bumpity bump.

I think this is a great idea. I actually extracted the rfid chip from one of my old debit cards and I'm thinking about having it placed right under my skin. I've seen a lot of people that have stainless steel balls and other things put underneath their skin for aesthetic purposes. I would love to see the look on the guy's face at McDonalds when I pay by waving my hand over the reader.

Don't flame me, guys, if you don't agree. No, it's not the mark of the beast, and no, it's not any more dangerous than a tattoo or something similar. There's a great video on Youtube of a guy that had one, albeit in a glass capsule, imbedded in his hand. That's where I got the idea.


The McDonalds employee might want to see the actual card itself or if unable to do that, accuse you of hacking the payment terminal. Then you have a problem. Manager, police, explaining, etc.
Now, imagine someone has a RFID killer with them. The chip heats up inside the glass capsule, the capsule shatters and the pieces are stuck in your hand, along with remains of the chip.
Algag xc10243 years ago
or someone has a reader in their hand go to shake their hand and boom your credit is ruined :/
Heck, I'm iffy about carrying a paypass card anywhere on me, nevermind in my hand. Plus the RFID identifier associated with your card will change anytime major information on your bank account changes. So it could be a useless RFID in your hand only months later. D:
AWarmGun2 years ago
After reading through the comments, I started pondering about the idea of putting the RFID chip in the memory card slot. (Note: I haven't attempted to construct this as of now, so I'm not familiar with certain specs and I'm brainstorming in a sense.) Do you think it would be feasible/possible to insert the RFID chip into an old, gutted memory card? If the acetone trick really does work, it'll greatly reduce the extra plastic. Hopefully it would fit into a memory card that has been popped apart. With this, if someone steals your phone, they should just think it's a busted memory card.

I also started pondering the worries a lot of people are having when it comes to the range of the RFID chips. I figured that If you manage to remove all of the excess card, leaving just the chip, you should be able to wire it to another metal portion of the phone (I was mainly thinking the antenna itself). However, if the memory card idea works, you could connect it to the grounding pin and it should use all the grounding "lines" on the chips as an extender.

As for security risks, due to RFID readers, killers, etc.. I THINK I might have a useful idea for that. Why not make a general case/cover for the phone able to block the signals? (I was thinking along the lines of modifying a body glove or similar) I'm not sure if lining it with something would do the job, if it would interfere with other aspects of the phone, or whatever else. I just figured that it would look "stock" and would protect the information while you're wandering about. Hell, you could even have a small section of the cover that easily flips open when required (preventing fumbling around & defeating the purpose), thus exposing the external part of the phone where the RFID card is contained within.

Hopefully this rambling has made a logical point or two, or at least help you guys ponder up some new ideas.
A copper screen mesh should block all signals.
dudesurge2 years ago
lame
francisroan3 years ago
hey then how will u ever put ur phone inside the atm slot?
Would be used for tap to pay systems. I believe ATMs read the strip and not the chip anyway.
Silence2 years ago
What if the phone has NFC enabled on it ? will this work with RFID systems ?
kkennedy43 years ago
If you are using a 'deactivated' card, how are you able to use it to pay for stuff when it is in your phone?
He obviously used a deactivated card only as proof of concept. I suppose that anyone in their right mind would first try locating and extracting the chip, and testing if it actually reads, before messing around with a working card.
Kikurimu (author)  NoobFest2 years ago
My bank issued me a second card because my first card's magnetic strip had stopped working. I figured why not put the RFID to good use?
I was very careful while doing this and was successful the first time.
i did very similar.
cut up an oyster card for the London tube trains, and stitched into the cuff of my leather jacket.
again, the strange looks when you just put your hand on the tap point and it works!
MJTH5 years ago
There used to be a show on TV called beyond tommorow that showed futuristic inventions. They showed a bus where as you walked on you just swiped your phone and as you walked off you swiped it again and it would charge you. That came out where I live, in australia just without the phone, we have little cards that have RFID chips in them. It says they belong to the place we bought them from soo im not game to cut it up, plus they wont give you a new one if you lose it and it costs 5 bucks plus whatever credit you have to top up (y) haha.
Here in Melbourne these are called Myki. They're replacing the melbourne metcard.
Spannerz MJTH3 years ago
Ahh, Go Cards :D South-east Queensland... in Brisbane City theyre pretty much a requirement haha. I chopped mine up and put the microchip in my blackberry ^^, the looks I get when I swipe my phone... >=]

Plus whos gonna care if you damage it xD they cost peanuts to produce and all you lose in the end is whatever money you had on it..
zack247 MJTH3 years ago
they have things like those in saskatoon too, theyre called "go passes" you place them on a stand at the front of the bus and the rfid reader scans and identifies the card, then you get on the bus.
i've had one apart before, but i have to say there is a lot less inside one than you might think.
No way! They're called Go Passes here, too! I did a little research when I moved from San Francisco to Brisbane, and the Translink cards we used in SF are owned by the Australia based Translink, which runs the "Go Pass" system here in Brissie. I wonder if Saskatoon is run by the same company?
hubologista3 years ago
Just cut my oyster card ( London travel card)and it it works , simple, easy and use full that's what i call a good hack :)
Nice :)
ranex3 years ago
whilst reading this i took my credit card and my smart phone- my credit card fits inbetween my smart phone and its case- it would work the same, but not as destructive
Treknology3 years ago
I did something similar with my laptop while at Uni. Most libraries use long metal strips that can be activated so that security stops you from leaving with a book that has not been logged as "on-loan", once it's logged and deactivated the security scanner lets you through, and then when you return the book the strip is re-activated.

I obtained such an activated strip from the staff and buried inside my laptop. This meant if a call of nature required that I had to ask someone else to keep an eye on it and they failed, it would be pulled up at security. Only I knew that I had to go to the counter and ASK for it to be passed around the security barrier.

Some of this technology can be turned to your own advantage.
wow, that's a smart one :-)
ella.mentry4 years ago
...couldn't you also do this by taping it to the inside of a cellphone's hardshell case instead?
bkapps4 years ago
This would be beneficial for people who lose their cards all the time, but people who lose their phones, not so much. Motorola RFID Reader is a great source to learn more about RFID reader information. 
Ranie-K4 years ago
You might be able to remove all the plastic (and expose the RFID chip) by simply dropping the hole card into acetone.

I saw that someone had done this and made the antennae bigger, so that it would get increased range.
kachup4 years ago
convinient way to pay but aren't your credit card details at an increased risk? the normal paypass card has visible security features which the store attendant can verify, if you hide it in the phone they can verify whether you're the legitimate cardholder or a guy who stole the phone.
Kikurimu (author)  kachup4 years ago
 True, it won't be visible as an actual card anymore, but it's also true that 99% of places that use the rfid credit card machines don't check. Also, with  this setup, if someone steals your phone, they would have to know what the heck that little piece of plastic in the phone was.
kachup Kikurimu4 years ago
you're right, but you know in some cases the thief is someone who knows you or has seen you use your phone to pay for things.
very cool. I'm not about to try it though, in fear of ruining both my card and Env2's micro sd slot.
lemonie5 years ago
You've manages to cut this without damaging the RF|ID aerial?

(Does it actually work?)

L
Agreed. I think you're cutting the antenna. That should drastically reduce the range at which it can be read, and may mess it up entirely. (RFID chips get their power from the base station through that antenna.) I'd be cautious with a card that means something or is difficult to replace.
I'd think the antenna bigger than the cut-out section, but perhaps not. Author says it works (other comments) L
jmeister155 years ago
haha, i cant wait to see the look on the cafiteria peoples face when i hand them this! They hate us when we pay with pennies!
muthaw5 years ago
Nice Idea
ralegg5 years ago
I don't have the card version of a paypass but I do have one of those plastic ones that you can put on a key ring and I want to try this out but I too wonder how many people have gotten it to successfully work. I'm worried about all the metal shielding from either the battery side or the faceplate side.
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