If a card is swiped through the USB Card Reader or the Mobile Card Reader, the processing fee per transaction is 2.75%.
If a card is manually keyed in by the Business or paid online by a Client, the processing fee per transaction is Stripe's standard rate of 2.9% + $0.30.
If either swiping or manually keying in an American Express card, the fee is always 2.9% + $0.30.