Won't allow me to put a tip on my credit card. I understand why you don't want to but in the end it will cost you much more then the taxes and processing fees. Your explanation of "We are trying to educate our clients that tipping is cash only" is laughable and makes no logical sense whatsoever. Your solution? Install a skimmer looking ATM which will costs the client $6 in fees in my case to leave a $7 tip? Another laughable solution. And the best part of all, That ATM is massive red flag that instantly tells an IRS Auditor, “This ATM dispenses cash for the sole purpose of funding unreported tip income.” When ATM transaction totals are matched against low reported tip income in the business, IRS will do its own math on tip percentage average from your credit card charges. That few hundred dollars a month it earns for the owner won’t put a dent in the back taxes and penalties that will be owed.