What a credit card payment processor does

A payment processor is the company that moves money from your customer's credit card to your bank account. When someone swipes, taps, or enters their card number on your website, the processor is the middleman that checks whether the card is valid, whether the account has enough funds, and whether the transaction should go through. Without a processor, you cannot accept credit cards at all.

The processor is different from your payment gateway (the software that collects the card information) and your merchant account (the bank account where the money lands). Many companies bundle all three together, which is why the terms get confused. But the processor's specific job is the communication — talking to the card networks (Visa, Mastercard, American Express, Discover) and the customer's bank to verify and settle each transaction.

Processors charge you a fee for this work. That fee is usually a percentage of the sale plus a flat amount per transaction, though the exact structure depends on your industry, your sales volume, and the processor you choose.

Key Takeaways

  • A payment processor connects your customer's card to their bank and your bank, and charges you a fee for each transaction.
  • Processor fees typically run 2.2% to 3.5% of the sale plus $0.30 per transaction, but rates vary by processor, industry, and sales volume.
  • You can use a standalone processor (Stripe, Square, PayPal) or work through your bank, and each route has different costs and support options.
  • Interchange fees (set by card networks) and assessment fees (set by card networks) are built into your processor's rate and are not negotiable.
  • Monthly volume, average transaction size, and your industry category all affect the rate a processor will quote you.

How processor fees are structured

Most processors charge you in one of three ways: interchange-plus, tiered pricing, or flat-rate. Each has a different cost depending on your business.

Interchange-plus is the most transparent. The processor shows you the interchange fee (set by Visa and Mastercard, not by the processor) plus a markup the processor keeps. For example, you might see "Interchange + 0.5% + $0.10 per transaction." Interchange itself ranges from about 1.5% to 3.5% depending on the card type and how the transaction was processed, so your total cost is visible but not fixed. This is usually the cheapest option for high-volume businesses.

Tiered pricing puts transactions into buckets — "may have access to," "mid-may have access to," and "non-may have access to" — each with a different rate. A may have access to transaction (a Visa debit card, for example) might cost 1.69%, while a non-may have access to one (an American Express corporate card) might cost 3.5%. The processor decides which tier each transaction falls into, so your actual cost is hard to predict. This is common with older processors and smaller merchants.

Flat-rate pricing charges the same percentage and per-transaction fee on everything — often 2.9% + $0.30. You know exactly what you pay, which is simple, but you pay the same rate whether the transaction is cheap to process or expensive. This works well for small businesses with low volume.

On top of the per-transaction fee, many processors charge monthly fees ($10 to $50), PCI compliance fees, batch fees, or statement fees. Read the full fee schedule before signing up.

Standalone processors versus bank-based processors

You can accept credit cards through a standalone processor like Stripe, Square, PayPal, or Authorize.net, or you can work through your own bank. Each route has trade-offs.

Standalone processors are faster to set up — you can often start accepting cards within hours — and they do not require a separate merchant account. They handle the technical side (the gateway and the processor in one) and deposit money into your regular business bank account. They work with any bank. Rates are usually published upfront, though they are not always the lowest. Support is often online chat or email, not a phone call to a person.

Bank-based processors are offered by your own bank or a bank they partner with. Setup takes longer (days to weeks) because the bank wants to review your business. But if you already have a relationship with your bank, they may offer you a better rate or waive some fees. Support is usually a phone call to someone at the bank. The downside is that you are locked into that bank's processor — if you switch banks, you have to renegotiate or switch processors.

For most small businesses, a standalone processor is simpler. For established businesses with high volume and a strong bank relationship, a bank-based processor may save money.

What affects the rate a processor quotes you

Processors do not charge everyone the same rate. Your quote depends on several factors that the processor uses to estimate their risk and cost.

Monthly sales volume is the biggest lever. A business doing $50,000 a month in card sales will get a better rate than one doing $5,000 a month, because the processor's fixed costs are spread across more transactions. Average transaction size matters too — a business with many small transactions pays more per dollar than one with fewer large transactions, because the per-transaction fee ($0.30 or so) is a bigger slice of the pie.

Your industry category affects risk. A grocery store is low-risk (the customer gets the product immediately, chargebacks are rare). A consulting firm or online course is higher-risk (the customer pays upfront, disputes happen later). A travel agency or furniture store is even higher-risk. Riskier industries pay higher rates.

How the card is processed also matters. A card present in your hand (swiped or inserted) is cheaper to process than a card-not-present transaction (online or phone). A keyed-in card (you type the number) is more expensive than a swiped card. Recurring charges (subscriptions) have their own rate, usually lower.

When you ask for a quote, be ready to tell the processor your monthly volume, average transaction size, and how you will process cards (online, in-person, phone). The more honest you are, the more accurate the quote.

Interchange and assessment fees you cannot avoid

Interchange fees are set by Visa, Mastercard, American Express, and Discover — not by your processor. They are the cost the card networks charge to move money from the customer's bank to yours. Interchange runs 1.5% to 3.5% depending on the card type and how it was processed. Your processor collects this fee from you and passes it to the card networks. You cannot negotiate it or avoid it.

Assessment fees are a smaller charge (usually 0.1% to 0.3%) that the card networks charge processors, who pass them to you. Again, these are not negotiable.

When a processor quotes you a rate, interchange and assessment are already built in. You cannot shop around to avoid them — they are the same no matter which processor you use. What you can shop around for is the processor's markup on top of those fees.

Chargebacks and disputes

A chargeback happens when a customer disputes a charge with their bank and the bank reverses the transaction, taking the money back from you. Common reasons are fraud, the customer did not recognize the charge, or the customer claims they never received the product.

When a chargeback happens, you lose the sale amount plus a chargeback fee (usually $15 to $100 per dispute, depending on the processor). If chargebacks are frequent, your processor may raise your rate or drop you as a customer.

To reduce chargebacks, use clear billing descriptors (so the charge is recognizable on the customer's statement), send order confirmations and shipping notifications, and respond quickly to disputes. Some processors offer chargeback protection or insurance, though it is usually an add-on cost.

PCI compliance and security

PCI compliance is a set of security standards for handling credit card data. If you store, process, or transmit card information, you must follow these standards or face fines and liability.

Most standalone processors handle PCI compliance for you — they store the card data on their secure servers, not on yours. You never see the full card number. This is the easiest and safest route for small businesses.

If you build your own payment system or use an older processor, you are responsible for PCI compliance yourself. This means security audits, encryption, firewalls, and regular testing. It is expensive and complex. For this reason, most small businesses use a processor that handles it for them.

Some processors charge a PCI compliance fee ($10 to $30 per month) even though they are the ones doing the work. This is a cost to ask about upfront.

Frequently Asked Questions

What is the difference between a payment processor and a payment gateway?

A payment gateway is the software that collects the card information (the form on your website or the card reader in your store). A payment processor is the company that verifies the card and moves the money. Many companies provide both, so the terms get mixed up, but they are two different functions.

Can I negotiate my processor fees?

You can negotiate the processor's markup, especially if you have high volume or a strong track record. Interchange and assessment fees are set by the card networks and are not negotiable. If a processor claims they can lower interchange, they are not being honest.

What happens if I process a card that turns out to be stolen?

If the cardholder reports it as fraud, you will lose the sale amount and pay a chargeback fee. You are liable for the loss. This is why processors care about your chargeback rate — too many chargebacks and they will drop you or raise your rate.

Do I need a separate merchant account?

Standalone processors like Stripe and Square do not require a separate merchant account — they deposit money into your regular business bank account. Bank-based processors usually do require a merchant account, which is a special account just for card transactions. Ask the processor before you sign up.

Why do some processors charge monthly fees on top of per-transaction fees?

Monthly fees cover the processor's costs for maintaining your account, customer support, and compliance. Some processors bundle these into a higher per-transaction rate instead. Compare the total cost, not just one line item.