Cash Discounts Allowed If...
Many gas retailers continue to ask NYACS whether it is legal to offer a discount for paying cash versus paying with credit.
Here is an answer from the New York State Bureau of Weights and Measures.
New York State adheres to National Institute of Standards Technology Handbook 44, the widely recognized bible for weights and measures standards. Handbook 44 says you can charge a lower price for cash, as long as :
1.) The customer is able to select cash or credit using the controls on the dispenser; and
2.) The dispenser window displays the correct price when the customer selects cash or credit.
To stay in compliance with state law, you would also need pump-topper signs displaying both the cash and credit price.
As for your gas-price signs out by the road, Weights and Measures advises that you don't need to post both the cash and credit prices, but whichever price you advertise on those signs, make absolutely sure it is clearly and correctly labeled as either the cash or credit price in letters large enough to read from the road. If consumers feel they are being misled, it's sure to generate complaints about your location.
Alos, check your MasterCard or Visa acceptance agreement to make sure, but typically such an agreement does not prohibit you from offering a discount for cash payment. If you charge a higher price for credit, that's considered a surcharge, which does violate the agreement.