TAMPA, Fla. (WFLA) — The owner of KiwiCup, a coffee shop in the Trinity area, is sounding the alarm after his business received two counterfeit $100 bills in a transaction.

“We had a customer come in—two consecutive customers come in actually—they presented us with counterfeit $100 bills,” said Luke Mayn, the shop’s owner.

Mayn said his employee even performed a quick and commonly-used pen test on the bills and determined they were real.

“Our girl at the register at the time did check the authenticity of the bills using the pens, but unfortunately they had some type of coating on the top of the bill which resulted in the pen displaying orange, which typically indicates it’s a real bill even though they were counterfeit,” Mayn explained.

For a small business, the $200 loss is significant.

“Unfortunately, it is quite a lot. If you can imagine how many cups of coffee that is, it’s a lot,” Mayn added.

KiwiCup is not the only small business in its plaza to be hit by counterfeit bills. In the past six months, three other businesses have suffered losses under very similar circumstances.

The Pasco County Sheriff’s Office reminds business owners they have the right to refuse large bills.

“If it’s a large $100 bill, and it’s a small purchase, and something doesn’t feel right—even if you’ve swiped the marker, maybe you are reading the character of the client at that time, maybe they are kind of impatient you could just say, can you pay with a credit card, I’m not comfortable with this,” said Pasco Sheriff’s Office spokeswoman Britney Morris.

Kiwi Cup has been using this as a learning experience while also warning others about the problem.

“From here on, this has been a great learning lesson for us,” Mayn said. “First of all, we want to spread an awareness to our community, so that other small business in the area are not caught up by this and secondly, we’d also stop accepting $100 and $50 bills for the time being until our staff is trained up.”