I think Amex is still more.
American Express Merchant Fees | Bankrate This is why you see MANY merchants that take MC/Visa but not Amex.
I've worked with a billing interface where one gets full card data, and the MC/Visa percent is a matrix - one axis is the vendor type, also incorporating things like "card present" or "card not present", and the other is the card tier (it's the category of card that influences the rate, not specific cardholder benefits - for example, a Visa Signature card carries a higher percentage than a regular visa. The percentage charged by merchant type is classic price discrimination - for example, gas stations and supermarkets pay a lower rate that retailers or dining establishments because a lower rate is needed to get business from the high volume/low margin businesses.
The merchant rate is also based on risk - for example, online merchants handling "card not present" transactions are in a higher risk category that "in your face card present" purchases.
Small merchants (for example, Hopkinton Sportsmens Association) tend to deal with payment processors like Stripe that charge something on the order of "2.9% + /.30 per transaction", not differentiated by card tier (the merchant is always charged enough to cover the most expensive card tier). Larger merchants in favorable categories use processors that do differentiate between card types. This can lead to the mistaken understanding among some merchants that there is no differentiation in the percentage based on the card tier .... because there isn't for them.
Debit cards have a much lower percentage fee. I've run into merchants that will take debit but not credit because of this... as well of those clueless enough to always run debit card usage as credit card charges.
It really depends on what you, as a merchant, can negotiate in writing, with your processor. For years, I dealt with shit processors who would routinely 'lie by exception' when it came to justifying their charges. We settled with Elavon who had much more transparent practices and policies, paid out much faster than other processors, and the technology was far superior to others. When it came to processing specific cards as of a coupe of years ago:
American Express (personal) had two tiers of charges: AESERV1 CP and AESERV2 CP. The first rate is 1.38% and the second is 2.80%. The difference between the two tiers is the kind of card: the lower rate card is just a basic AMEX card and the second rate is a rewards card, corporate card, or other loyalty/branded card. By comparison, VISA and MC fees range between 1.22% to 3.35% depending on the card used and the loyalty tiers involved. With the variety of cards out there, you have to call each issuer and ask them for a full list of cards and what tier that particular card falls into. It was an absolute pain in the ass to do this when we were dealing with prior processors because we didn't trust they were categorizing them correctly. It was interesting that an Amex Platimum was cheaper to process than a Capital One Visa.
There are four tiers of rates merchants are charged: qualified rate, partially-qualified rate, commercial non-qualified rate, and non-qualified rate. A merchant cannot determine which category a card falls under but the actions they take when processing these cards can affect what tier they fall into. If it is a commercial card, you can assume it falls under a commercial non-qualified rate and if it is a rewards or loyalty card we can assume it falls under a partially-qualified rate.
Rates for V/MC/DISC were:
1. Qualified rate - 1.22% + 0.12
2. Partially-qualified rate - 1.99% + 0.19
3. Commercial non-qualified rate - 2.65% + 0.29
4. Non-qualified rate - 3.35% + 0.29
Rates for Amex were:
1. Qualified rate - 1.38% + 0.19
2. Partially-qualified rate - 2.80% + 0.29
3. Commercial non-qualified rate - 3.50% + 0.29
When presented with a debit card, when we made sure to process it as a debit card because there were no percentage processing fees associated with it, just the 0.12 per transaction charge. If it is processed as a credit, all credit card processing fees are levied against the charge.
If the terminal prompted me for additional information, like a PIN, zip code or a CVV number, input it and do not skip over it. Skipping either step can send the charge from a qualified rate to a non-qualified rate. Closing the batch daily also ensures that all available charges get processed at the lowest possible rate. Keeping the batch open for more than 24 hours automatically pushes the charges to the next higher tier rate.
Within the four rats of V/MC/DISC there were various different levels of sub-tiers of categories. All of those sub-sections will be within one of the four main tiers.
There is also a nominal charge, usually between a dime and a quarter, per transaction. There are other determinations, like you mentioned, with 'card not present' or overriding the billing zip code request, which raises the fraud potential and therefore automatically pushes the transaction into the highest possible processing tier.
This is for a small business which was processing between 10-50 transactions per day on a seasonal basis and we found it worthwhile to stay with Elavon for subsequent renewal periods.
Details are for anyone dealing with merchant processing charges. Going through this and relaying best practices with employees can really make a difference in your margins.