Credit Card Processing Fees Explained
Interchange, assessments, markup, flat rates, and the effective rate you should actually track each month.
Last updated: March 2026
Merchant statements look complicated on purpose—but a few ideas unlock most of them: whether you are on flat-rate or interchange-plus pricing, how card-present vs not-present affects cost, and the single number (effective rate) that tells you what you really paid last month.
Pair this guide with our Helcim and Stripe reviews and the best payment processing software roundup when you compare vendors.
Flat-rate pricing
Simple percentages until volume changes the math.
One blended percentage simplifies budgeting and protects teams from reading dense statements—until average tickets grow large enough that basis points matter. Many trades start here with Square or simple Stripe tiers.
Interchange-plus pricing
Transparency on statements—and more to reconcile.
Statements separate interchange (network cost) from processor markup. Finance-heavy owners prefer this transparency when negotiating renewals or comparing ISO quotes. Evaluate Helcim vs Stax when membership models enter the picture.
Card-present vs not-present
Why swipes usually cost less than keyed or online.
Swipes and chips usually cost less than keyed numbers or online invoices because fraud risk differs. Train crews to tap when possible—savings compound across hundreds of jobs.
Service-business examples
Mixed channels on one job.
A $9,000 HVAC replacement with a 50% deposit online and balance swiped on site mixes rates—compute effective rate on the whole job, not each leg in isolation. That number should drive processor decisions.
FAQs
Quick answers to common questions.