Counterfeit money in the USA has become such a prevalent problem it is possible you could receive counterfeit cash in your change when you purchase something at leading retailers like Walmart.
Most large retailers do not wish to spend the time or money to properly train their employees in how to spot counterfeit money. Insteadthey rely upon those marking pens that contain ink which supposedly changes colour when marked on fake money.
The reason the ink would change colour when indicated on a counterfeit note is that nearly all fake notes are made of paper.
Money is not made of paper, so it’s made of cloth, a blend of 25% linen and 75% cotton. That is why cash feels the way it does.
But most do not understand that many of these pens will tell you the exact same thing when pronounced on ordinary newspaper - it’s real! A lot of those counterfeit note marking pens don’t work. Very few people think to examine them and therefore are unaware of the.
So it is very possible a shop clerk will take in fake money and set it in the till without realizing it’s fake.
Obviously, the clerk makes change out of the same till, also gives the exact same fake cash to an unsuspecting customer.
You might even have counterfeit money in your billfold at this time and not know it.
Real or counterfeit - can you tell the difference?
Most Americans do not have a clue.
One of the simplest ways to tell would be to feel it. Since actual cash is printed on fabric, if you are feeling copier paper it’s probably fake.
College students are not the smartest people on Earth. will buy the most advanced color copiers and simply make copies of a $10 notice or even a $20 note and try to pass them around town.

They forget that not only does it not feel like fabric, but every single note will have the specific same serial number as the first.
If someone hands you more notes of the same denomination, check the serial numbers. If they match, call the police immediately because one or all of them are counterfeit.
You will find approaches counterfeiters will use to get around the issue of this feeling like paper and also the sequential numbers not being different.

One of the most common approaches is to take four $10 notes or four $20 notes and cut one corner from each of them and paste those corners on a one-dollar note.
All of a sudden these $1 notes turn into fake $10 notes or fake $20 notes that not only feel just like actual notes but also have different serial numbers. They’ll also pass the fake pen test.
Then they use these doctored notes to buy items for just a buck or two and the clerk gives them actual money back as change (assuming the clerk has not previously taken in counterfeit notes of course.)