Get your wallet out and open it up. You might be holding on to fake money and not even know it.

It's not just customers getting scammed. Many local businesses along North Florida Avenue in Tampa, also are victims of counterfeit money.

"Every dollar matters, every penny matters. So when someone comes with fake money it's not only hard to keep business afloat but it's insulting," says Greg Spadaccini, owner of Spaddy's Coffee.

In the past week, Spaddy’s has been hit twice with fake bills.

Spadaccini posted the fake 20s with tape inside his business, as a reminder to constantly check all money even the $10 bills. When the tape, was ripped, you could see it was printed on paper.

Mauricio Faedo's Bakery next door along with the Independent Bar and Café were also targeted.

Down the street, the owner of Smoke Signals, Jason Newman, also feeling the pinch of losing money.

"We're new stores so we're kind of unsure of ourselves in some ways. So, they prey on that,” says Newman.

"We're just trying to make an honest living people are doing the complete opposite," says Spadaccini.

Many local business use counterfeit pens to see if the money is real, but Billy Joe Powers, who has been with the Secret Service for 21 years, says it’s not a good idea.

"This is a $1 note where all of the ink has been removed and made into a $100 bill. So, if you use a counterfeit pen then you will be like it's fine, its real money,” says Powers.

Powers says everyone should also be concerned about fake money. If you don’t know your currency, then you are just as vulnerable.

"There is enough anticounterfeiting measures that are built in the money. So, if you own a business you should ensure people handling the money are that familiar,” says Powers.

Here are some tips from the Secret Service's website for detecting counterfeit bills:

PAPER: American currency is made of 25% linen and 75% cotton. It also contains red and blue security fibers throughout the paper.

COLOR-SHIFTING INK: The 2004-style $10, $20, $50 and $100 Federal Reserve notes have color-shifting ink that shifts from copper to green when tilted at 45 degrees.

Click here for more info on detecting fake currency