That’s actually not true, the only time you have to take 100’s is when there’s a debt being settled. Even if it were a law, what are you going to do? Call the cops because your too dumb to carry under a 100 dollar bill? Your the one using a 100 which puts the employees at higher risk of robbery. Also, businesses aren’t legally obligated to purchase counterfeit testing equipment, which is necessary if your business is taking 100’s. Businesses have the right to refuse service especially under the right circumstances and 100’s are always suspicious because they are one of the most commonly counterfeited bills. It would be very easy to justify refusing service.