How many times have you stuffed cash into your wallet, without really looking at the bills? Authorities say it's worth a second look because there is an increase in the amount of counterfeit cash circulating the Southeast. The U.S. Department of Homeland Security and the Secret Service are warning local law enforcement and you ---to be on the lookout. 

"Even if you're receiving change, you need to take a good glance at it," said Sheriff Gary Sisk, Catoosa County. "If it doesn't feel right or doesn't look right, you need to take a minute to look at it."

Catoosa County Sheriff Gary Sisk showed Channel 3 dozens of $100, $20, and $10 counterfeit dollar bills seized by local authorities. He shared a warning on the Department's Facebook page to warn local residents about the types of fake bills being passed around. 

"We see a good bit more of your $10s and $20s because typically a high dollar bill raises someone's suspicions anyway... so they are going to inspect that a lot closer than a smaller bill," said Sisk. 

Otto Boehm knows all too well- how important it is to take a second look, his building materials business " Junior's" has been paid in counterfeit cash leaving him out hundreds of dollars. 

"If it's counterfeit, it's just out of my pocket... it's gone," said Boehm. 

His staff is now on high alert. In addition to checking all of the bills passed, they've installed security cameras around the store. 

"They mark it, we look it through for the line, we twist it to see the color change and the watermarks," said Boehm. "If you have a lot of money coming through, we check it good."

To be absolutely sure a $20 dollar bill is real, you can hold it up to the light and see an embedded security thread, that reads "Twenty USA" from top to bottom. All bills have a security thread except for $1 and $2 dollar bills. A watermark of the portrait on the bill should also be on the right side and color shifting ink that appears to change when the bill is tilted also helps to identify a real from a fake. On some bills, the ink will also "bleed" when the bill is wet. 

"You watch it, you look close... if there is any doubt just ask where they got their money," said Boehm. 

For more information on how to detect counterfeit money visit:

Secret Service agents out of Chattanooga tell Channel 3 their department receives about 20,000 fake bills each month. Officials say some fake bills are even passing the trusted black marker test. 

The U.S. Secret Service asks businesses and individuals to be on the lookout for suspicious currency. If someone attempts to pass a counterfeit, try to obtain as much information as possible about the individual(s). Call local police and the Chattanooga office of the U.S. Secret Service at 423-752-5125. If you try to pass a fake bill, knowing it is fake- you could be charged with a crime.