Payment processing fees, compared

The short answer

Published flat card rates on the 12 flat-rate providers below run from 2.29% to 2.9% plus, for most, a fixed fee per transaction; interchange-plus providers are listed with their markup. The gap between providers often matters less than how each payment is taken: tapped, keyed, sent as a link, or moved to ACH, where some providers cap the fee and others charge an uncapped percentage. Each page lists one provider's published rates, its fee traps, and a calculator for your own volume.