Credit Card Processing Fees for Small Business: Interchange Explained

The short answer

Every card payment you accept carries three layers of cost. Interchange goes to the cardholder's bank (the issuer) and is set by the card networks. Network assessments go to the card network itself. The processor's markup is what your payment provider charges for its service. Interchange is usually the largest piece, and you can't negotiate it directly — but you can control which pricing model you're on, the markup you pay, and how your transactions qualify.

What interchange is

Interchange is a fee paid from the merchant's side of the transaction to the card-issuing bank. Card networks publish interchange tables with hundreds of categories. The rate on a given sale depends on factors like:

• Card type: debit, standard credit, rewards credit or business/corporate card
• How the card was accepted: chip or tap in person vs. keyed or online
• Your merchant category (industry)
• Data passed with the transaction, such as address verification or business-card details
• Settlement timing — batches settled late can cost more

Debit cards are different

Under the Federal Reserve's Regulation II, interchange on debit cards issued by banks with $10 billion or more in assets is capped. The Federal Reserve publishes the current cap, which combines a fixed per-transaction amount, a percentage of the sale and a small fraud-prevention adjustment. Debit cards from smaller issuers are exempt from the cap. This is why debit transactions usually cost less than rewards credit cards.

Network assessments and processor markup

Assessments are smaller fees charged by the card networks on volume and transactions. Processor markup is the provider's margin and can appear as a percentage, a per-transaction fee, a monthly fee or all three. Markup is the negotiable part.

Pricing models

• Interchange-plus (cost-plus): you pay actual interchange and assessments plus a disclosed fixed markup — the most transparent
• Flat rate: one blended percentage plus a per-transaction fee — simple to understand, but low-cost debit transactions are priced like expensive ones
• Tiered: transactions sorted into "qualified," "mid-qualified" and "non-qualified" buckets — hard to audit
• Subscription/membership: a monthly fee plus interchange and a small per-transaction fee

Calculate your effective rate

The single best number for comparing providers is your effective rate: all fees divided by all card volume for the same month.

Worked example (hypothetical)

• Monthly card volume: $80,000 across 1,000 transactions (average sale $80)
• Interchange: $1,480; network assessments: $110
• Processor markup: 0.30% of volume ($240) + $0.10 per transaction ($100) + $25 monthly fee
• Total fees: $1,480 + $110 + $240 + $100 + $25 = $1,955
• Effective rate = $1,955 ÷ $80,000 ≈ 2.44%; annual cost ≈ $23,460
• Same volume on a 2.90% + $0.30 flat rate: $2,320 + $300 = $2,620 ≈ 3.28%
• Difference: $665 a month, or about $7,980 a year — for this hypothetical mix only

Ways to lower costs

• Read one recent statement and calculate your effective rate
• Ask for interchange-plus pricing with the markup in writing
• Accept chip and tap in person rather than keying cards
• Pass address verification and, for business customers, required order data
• Settle batches daily
• Remove fees you don't use (statement, PCI non-compliance, unused gateways)
• Review surcharging or cash-discount programs only with qualified advice — they carry card-network rules, state laws and disclosure requirements

Taxes and recordkeeping

Card processing fees are generally an ordinary and necessary business expense. The IRS explains the rules for deducting business expenses; your tax professional can confirm how they apply to you. Keep monthly statements so fees reconcile to your books.

How to read your statement in ten minutes

You don't need to understand every line to find your effective rate and spot obvious markup. Look for these items on one recent monthly statement.

• Total card volume (sometimes called gross sales or amount submitted)
• Total fees charged for the month, often on a summary page
• Interchange and assessment totals, if the statement separates them
• Processor fees: percentage markup, per-transaction fees, monthly, statement, PCI and gateway fees
• Any non-qualified or downgrade charges, which point to transactions that cost more than they should
• Divide total fees by total volume, write that rate down and compare it against written quotes using the same month

Common questions

Sources

• Federal Reserve: Regulation II (debit card interchange)
• IRS: Deducting business expenses