Flat rate vs interchange-plus
Flat rate means one percentage (and often a small per-swipe fee) no matter which card a guest uses. It's easy to read on a statement.
Interchange-plus passes through what the card networks and banks charge (interchange), then adds the processor's markup on top. Rewards cards cost more, debit cards less. It's harder to read but often cheaper once your volume grows.
swipes = card sales ÷ average ticket monthly fees = sales × rate + swipes × per-swipe fee + monthly fee effective rate = monthly fees ÷ card salesA worked example
$50,000 in card sales at a $50 ticket is 1,000 swipes. At 2.6% plus 15¢ that's $1,300 + $150 = $1,450 a month. At 1.9% interchange plus 0.3% markup, 10¢ a swipe, and $25 a month, it's $1,100 + $100 + $25 = $1,225. The second plan saves $2,700 a year.
How to find your real numbers
Take last month's statement. Divide total fees by total card sales: that's your effective rate, the one number that lets you compare any two offers. If it's above about 3%, it's worth a second quote.
Questions owners ask
Can I pass the fee on to guests?
Surcharging and "cash discount" programs are allowed in many states but come with card-network rules and state limits, and they can annoy regulars. Check your state and your processor's rules first.
Does the fee apply to tips on cards?
Yes. The fee is on the full amount charged, tip included. That's why this calculator uses total card sales.