Every payment processing quote you receive comes down to one of two pricing models: flat-rate or interchange-plus. The difference between them — in transparency, cost, and fit for your business — is the most important thing to understand before signing with any processor.
Most small businesses default to flat-rate pricing because it is how Square, Stripe, and Toast are set up, and those are the processors most business owners encounter first. That default costs many businesses thousands of dollars per year without their awareness.
How Flat-Rate Pricing Works
Flat-rate pricing charges a single percentage plus a per-transaction fee on every card transaction, regardless of what card the customer uses.
Square charges 2.6% + $0.10 for in-person transactions. Stripe charges 2.9% + $0.30 online. Toast Payments charges 2.49% + $0.15. In every case, the same rate applies whether the customer swipes a basic debit card, a Visa Signature rewards card, or a corporate purchasing card.
This is intentional. Flat-rate processors average across their entire merchant base and set a rate high enough to cover their average interchange cost with enough margin on top to remain profitable. When your customers pay with low-cost card types (debit, basic credit), the processor keeps the difference. You do not see the breakdown.
For a business just starting out under $10,000 per month in card volume, flat-rate’s simplicity often justifies that premium. Above that threshold, it rarely does.
How Interchange-Plus Pricing Works
Interchange-plus pricing separates the cost of processing into its actual components. You pay the real interchange rate for each transaction — set by Visa and Mastercard and published publicly — plus a fixed markup from your processor.
The markup is where processors compete. A competitive interchange-plus account for a small business typically runs 0.20% to 0.40% plus a per-transaction fee on top of interchange. That markup covers the processor’s cost of service, risk management, and profit margin.
Your statement on an interchange-plus account shows exactly what you paid in interchange on each transaction type, what the assessment fee was, and what your processor’s markup was. You can see and verify every component of your cost. Nothing is bundled.
The Three Cost Layers Behind Every Transaction
Every card transaction passes through three cost layers. Understanding them is the key to evaluating any quote.
Flat-rate pricing bundles all three into one number. Interchange-plus shows all three separately — which is why it is sometimes called “cost-plus” pricing.
What the Savings Actually Look Like
Here is a monthly savings comparison for a business processing $60,000 per month with a typical card mix (45% debit, 45% standard credit, 10% rewards):
Run your actual numbers through our free rate comparison tool to see exactly what your volume would cost on a competitive interchange-plus account.
When Flat-Rate Pricing Makes Sense
- Under $10K/month in card volume
- Occasional or seasonal sellers
- Businesses just starting out
- Stripe for complex SaaS/e-commerce
- Margins too strong to care
- Over $15K/month in card volume
- High debit card mix
- B2B or high-ticket transactions
- Restaurants, retail, healthcare
- You want statement transparency
Low volume. Under $8,000 to $10,000 per month in card transactions, flat-rate pricing’s premium is relatively small in dollar terms — often $30 to $80 per month. The absence of monthly fees and the simplicity of the relationship often justifies that premium for a business just starting out.
Complex online infrastructure. Stripe’s developer tools, webhook system, subscription billing engine, and API ecosystem are genuinely industry-leading. Many SaaS companies stay with Stripe not because of its pricing model but because rebuilding their payment infrastructure is not worth the engineering cost. Large Stripe users should negotiate custom pricing — Stripe offers it for businesses above $250,000 per year.
What to Watch For in Interchange-Plus Quotes
Not all interchange-plus quotes are equal. Here is how a less-than-transparent processor can make an account look attractive and then be expensive in practice.
High per-transaction fees. A markup of 0.15% + $0.25 per transaction sounds low in percentage terms. On a business with a $30 average ticket and 1,000 transactions per month, the $0.25 per-transaction fee alone is $250. Evaluate the full cost, not just the percentage.
Excessive monthly fees. Some interchange-plus accounts layer on gateway fees, PCI compliance fees, annual fees, statement fees, and batch fees totaling $50 to $100 per month. A well-structured account should have combined monthly fixed costs under $30. Ask for a complete list of all fees before signing.
Non-qualified surcharges. Some processors use a hybrid called “enhanced recover reduced” (ERR) or tiered pricing dressed up as interchange-plus. Ask specifically whether your quote is true interchange-plus with a single flat markup, or whether there are surcharges for specific card types.
Long-term contracts with ETFs. Reputable interchange-plus processors offer month-to-month agreements. Any contract with an early termination fee above $250 warrants scrutiny. Our guide on how to switch payment processors covers what to review before signing.
How to Calculate Your Current Effective Rate
You do not need to understand interchange tables to figure out whether you are overpaying. Divide your total monthly processing fees by your total monthly card volume.
For a detailed breakdown of how to read your statement and identify hidden fees, see our guide on why your processing statement may be misleading you.
Lucrative Merchants provides transparent interchange-plus accounts for small businesses throughout the Pacific Northwest and nationally. We work with retail, restaurant, professional services, e-commerce, and specialty industries — including those that require a high-risk merchant account.
Month-to-month agreements. No early termination fees. Full statement transparency on every transaction. The gap between what you are paying and what you should be paying is almost always larger than you expect — and the switch is simpler than you think.
