Instructables
video How to detect Fake MONEY (USD)


Easily spot counterfeit money at home with this trick, without any special equipment. Enjoy.
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UPDATE: (infos from different sources)
Many of the early bill changers took advantage of the fact that U.S. bills are printed with magnetic ink. They could therefore use magnetic heads (like the ones in a cassette tape recorder) to pick up signals from the bills. Areas of the bill (like the background behind the president's face) would generate signals at a specific frequency, and the detection of this frequency would validate the bill. Different bills generate different frequencies, so the frequency can also help determine what the denomination is.Many of the early bill changers took advantage of the fact that U.S. bills are printed with magnetic ink. They could therefore use magnetic heads (like the ones in a cassette tape recorder) to pick up signals from the bills. Areas of the bill (like the background behind the president's face) would generate signals at a specific frequency, and the detection of this frequency would validate the bill. Different bills generate different frequencies, so the frequency can also help determine what the denomination is.

# Genuine dollar bills have a certain conductivity, and checking for the resistance of a bill can authenticate it.
# Inks and papers have different fluorescent properties, and these properties can help tell real from counterfeit bills.

It is a special ink that CANNOT be removed. If no ink shows up it means the bill is a counterfeit.
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You can check this video on metacafe or my channel for other "how to" videos.
h88642 years ago
at gap they cannot report shoplifters and the must accept money unless one side is white. You could use a 1 mil bill and they couldn't stop you.


YOU CAN BUY LEATHER PANTS!!
Havvk4 years ago
Or you can just buy one of those pens and save yourself the trouble.  
tmosher Havvk3 years ago
Except that doesn't work with really good funny money. Skilled counterfiters will either bleach out one dollar bills to print over, or buy starch free paper. Either way those pens will give a false negative.

And lets be honest, if it's not a good fake (printed on a bleached bill or starch free paper that closely resembles the true composite of bills), you should be able to tell just from the feel of the paper. Upon a feel fail test, all you've got to do is look for watermarks and microprinting.
KnexFreek4 years ago
 AWESOME!!!!!!!!!!!!!!!!!!!!!!
vianka996 years ago
if the money did not follow the magnet, it's fake?
if the bill was realy crumpled up it might not work

dodo915 years ago
there is also another way. hold a bill in the light. a secret image should appear. 5$- three five on the left and one five on the right 10$- before- a white circle after- a head shold appear in the circle 20$- TWENTY USA, USA TWENTY should dissapear, and a head should appear next to the twenty with a green circle thing on it.
toelle5 years ago
what would happen if you put a real dollar bill in a ctr scanner? :P
U mean just to say ... reproduce it? No this would not work because money is printed on a special type of paper...... actually it is not paper it is fabric, besides they use special types of ink all kinds of security measures. Therefore it almost impossible to counterfit money. I know somebody is going to say this so I will correct myself, I said ALMOST impossible.
No I didnt mean to reproduce dollar bills. I just meant that it would be pretty cool because ctr scanners are just really strong electromagnets.
dehlome5 years ago
i tried it and it didnt work!!!!:@
Flumpkins6 years ago
Hey blindsight, i have another suggestion, why not sniff the bill? lol
Dollar bills Always have the same scent. Usa bills do at least.
Crap, my money has been in my wallet for a while now and now they smell like leather :)
usually they smell like paper or just the hands of the entire country.
hands of the country?you mean poop?
Not if its Canada :P
hahaha yeaH!
Wait... I mean no! I'm from USA!
LOL
rightbackatcha
Not to be mean or anything, but wont any counterfeiters who look here will now know to add iron particles to money.....
shaadiya6 years ago
i am asking whether there is real Black USD money that are coated in black ink which can be removed and then turns in to real Dollars?
moomoocows6 years ago
I also have an interesting fact here. The magnetic strip is sandwiched in between two layers so if you notice where the magnetic strip is you can make a little tear in the bill and then work the magnetic strip out of the bill. I don't advise doing this if you plan to use the bill in a vending machine because I think that's how the machine distinguishes between a one and anything else. O and a side note one dollar bills will not have a strip in them. If anyone knows if that's how the vending machines tell the difference please inform us thanks.
i have a flawless easyer way. All you need is a black light, take the black light and run the bill on top of it, you will see a bright yellow line somewhere in the bill running verticly threw the bill (very visible, dont worry.) if you see it then the bill is fake. Or also you could just buy a cheap bill-pen (your write on a bill, if it turns yellow its real, if turns black its fake!). but the blacklight is flawless! :-D
andrew, how would you get a black light?
ok your can buy a black bulb, pretty much any hardware store, or definatly at a doller store, or a party store :-). Thos just work like a normal light (screw in), but for me, i got a nice 15 inch ....'lol thats what she said'... florecent tube bulb and the holder at a garage sale for a doller!! :-D. the tube ones work best, but the bulb ones work well to.
1$ on a pen or 5$ money detector at radio shack.
Maxx16 years ago
I just tried all the bills I have including the ones I got from the bank today. No go on any of them.
BlindSight (author)  Maxx16 years ago
Hi Maxx1, As I said in the video, you need a magnet strong enough (In the video I'm using 5 fridge magnets, but 1 only neodymium is enough). Bye, and thank you for your interest in my stuff ;)
ac1D6 years ago
Just tried with a 10$ CANADIAN bill, and ths trick wont work for uss..
mrmath ac1D6 years ago
I was just going to say that the author might want to have named this How to detect fact US MONEY. It's interesting that Canadian bills aren't magnetic, but Canadian coins are, while US coins aren't magnetic, but apparently, US bills are. OR, maybe, just maybe, your bill was FAKE! :O
BlindSight (author)  mrmath6 years ago
haha, good point. I edited the title following your suggestion :)
trooperrick6 years ago
I just tried it and it works!! But it seems to be only attracted to the black ink on the "heads" side. Thats really cool.
i could only get it to work on the tree on the whitehouse side on a $20