How it works
Most card processing pricing has two parts: a percentage of the sale and a fixed fee per transaction. The fixed part is why small sales cost proportionally more to accept.
Example. On a $25.00 sale at 2.9% plus $0.30, the fee is $1.03 and you keep $23.97. That's an effective rate of 4.1%.
To walk away with the full $25.00, you'd have to charge $26.06.
Across 1,200 card sales like that in a month, fees add up to $1,230.
Small tickets cost more
On a $3 purchase at the same pricing, the fee is about $0.39, an effective rate near 13%. That's why some stores set a card minimum. Card network rules and state laws limit how minimums can work, so check with your processor before posting one.
Passing fees to customers
Adding a surcharge or running a cash discount program can offset fees, but the rules are strict. They differ by state and card network, surcharges generally can't be applied to debit cards, and most require clear signs and advance notice. Talk to your processor about what's allowed before you change how you price.
Common questions
- Why doesn't my statement match this exactly?
- Many processors use interchange-plus or tiered pricing, where the rate depends on the card type (rewards, business, debit) and how it was taken (tap, chip, keyed). Use your blended rate, total fees divided by total card sales, for the closest estimate.
- Where do card fees go on my books?
- Usually as an operating expense rather than cost of goods sold. For fuel, where fees can take a big share of the margin, the fuel margin calculator includes them per gallon.
Last updated October 11, 2026.