Carrollton police are asking cashiers to be on the lookout for counterfeit money circulating after police received two fake bills within the past five days that had been used to buy fast food.

Police Lt. James Perry said drive-through cashiers at two Carrollton fast-food chains — including Zaxby’s on South Park Street — were given counterfeit bills to pay for customer’s orders last week.

Perry said in one instance a man, who witnesses described to police as very scared, became so nervous that he placed an order through the drive-through and then drove off after handing the cashier a counterfeit bill before he even received his food.

Perry said the $5 and $20 fraudulent bills in the two cases were turned into police after employees realized the money was not legitimate. The $5 bill, Perry said, appeared more authentic looking on the front of the bill but lacked many security features when it was turned over.

“The bills could have been photocopied,” he said. “These were not quality counterfeit bills and were printed on regular paper. We are asking businesses to check the money they receive.”

Perry said one of the bills was not detected until a manager at the restaurant was counting the money to make a deposit and saw the fake bill. Police have a suspect in one of the cases, and are investigating to see if the two incidents are related.

Perry said that although each counterfeit bill can vary in appearance, cashiers handling money should check for a bill’s color. Often a counterfeit bill will be either brighter or darker than average. Security features are also missing, such as the authentication strip or holographic images.

“A lot of times the face of the bill might appear real, but the back of the bill might have problems,” he said. “It is easier for a criminal to make a forgery on one side but more difficult on both sides.”

Perry said it is not uncommon for someone trying to pass counterfeit money to use the bills to make small purchases — such as fast food — to obtain the change from the purchase.

Anyone with any information on the incidents can contact the detective unit at the Carrollton Police Department at 770-834-4451.