What a credit card payment processor does

A credit card payment processor is the company that moves money from your customer's 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 have no way to accept cards at all.

The processor is different from the payment gateway (the software that collects the card information) and different from your merchant account (the bank account where the money lands). Many small businesses use one company that handles all three, which makes it simpler but also means you're locked into their pricing on everything.

Processors make money by taking a cut of each transaction. That cut is usually a percentage of the sale plus a flat fee per transaction — for example, 2.9% plus $0.30. The exact rate depends on the type of card, how you accept it, your industry, and your sales volume. A restaurant processing in-person Visa transactions pays a different rate than an online boutique processing American Express.

Key Takeaways

  • A payment processor connects your customer's card to your bank account and takes a percentage plus a per-transaction fee for doing so.
  • Rates vary by card type, how you accept the card (in person, online, phone), your industry, and your monthly volume — not all processors quote the same price.
  • Interchange fees (set by Visa and Mastercard) are the largest part of what you pay and are the same everywhere; processor markup is where you can negotiate.
  • Monthly fees, statement fees, and PCI compliance fees add up and are often hidden in the fine print until you see your first bill.
  • Switching processors is possible but requires new equipment or software integration, so choosing carefully the first time saves time and money.

How much a processor charges

The fee structure has three layers. The first is interchange, which is the fee Visa, Mastercard, Discover, and American Express charge. You cannot negotiate this — it's the same whether you use Square or your bank. Interchange is usually 1.5% to 2.5% of the transaction, depending on the card type and how you process it.

The second layer is the processor's markup, which is their profit. This is where you can negotiate. A processor might add 0.5% to 1.5% on top of interchange, or they might charge a flat monthly fee instead of a percentage. Some processors quote "interchange-plus" pricing, which means they show you the interchange fee separately and then add their markup on top — this is usually more transparent than a bundled rate.

The third layer is everything else: monthly account fees (often $10 to $30), statement fees, PCI compliance fees, gateway fees if you're processing online, and fees for chargebacks or disputes. These add up quickly and are often buried in the contract. Ask for a full fee schedule before you sign up, and ask specifically whether there are monthly minimums or cancellation fees.

Payment processors for in-person sales

If you accept cards at a physical location, you need a terminal or a mobile reader. Square, Toast, Clover, and Ingenico all make hardware that connects to your phone or register. The processor is built into the device — you don't choose them separately.

Square and Toast are popular with small businesses because the hardware is cheap or free, and the rate is the same for everyone (no negotiation, but also no surprises). Clover and Ingenico are more common in restaurants and retail because they integrate with point-of-sale systems and offer more customization. The trade-off is that setup is more complex and rates are higher.

If you already have a merchant account with your bank, you can ask whether they offer a compatible terminal. Many banks have their own processors or partnerships, and using them might save you money if you're already paying monthly fees there.

Payment processors for online sales

Online businesses typically use a payment gateway like Stripe, PayPal, Square Online, or Shopify Payments. The gateway collects the card information on your website and sends it to the processor behind the scenes. For most small online businesses, the gateway and processor are the same company.

Stripe and Shopify Payments are popular because they're easy to set up and the rates are published upfront — usually 2.9% plus $0.30 per transaction for online cards. PayPal charges similar rates but has a longer history and integrates with more shopping carts. Square Online is cheaper if you're also using Square for in-person sales, because you get one rate across both channels.

The downside of these all-in-one services is that switching later is harder. Your transaction history, customer data, and recurring billing are all locked into their system. Before you choose, ask whether they can export your data and whether there are any fees to close your account.

Interchange-plus versus bundled pricing

Interchange-plus pricing shows you two separate charges: the interchange fee (which you can't change) and the processor's markup (which you can). This is more transparent because you can see exactly what the processor is taking. If you process $10,000 in Visa transactions at 1.8% interchange plus 0.5% markup, you pay $230 in processing fees — $180 to Visa and $50 to the processor.

Bundled pricing combines everything into one rate. The processor quotes you 2.9% and doesn't break down how much is interchange and how much is their markup. This is simpler to understand at first, but it means you can't tell whether you're getting a good deal. Different card types have different interchange rates, so a bundled rate might be cheap for Visa but expensive for American Express.

For most small businesses, interchange-plus is better if you process high volume (over $5,000 per month) because the savings add up. For lower volume, bundled pricing is often simpler and the difference is small. Ask your processor for both quotes and do the math on your actual card mix before you decide.

Hidden fees and what to watch for

Read the contract carefully and ask about these specific fees: monthly minimums (some processors charge you even if you don't process anything), statement fees (usually $5 to $10 per month), PCI compliance fees (for storing card data securely), gateway fees (if you're processing online), batch fees (per day you settle transactions), and chargeback fees (when a customer disputes a charge).

Some processors also charge setup fees, equipment fees, or early termination fees. If you're locked into a contract, leaving early can cost hundreds of dollars. Ask whether the contract is month-to-month or fixed term, and whether there are any penalties for closing your account.

The best protection is to get a written fee schedule before you sign anything, and to ask your processor to walk you through what your first month's bill will look like based on your expected sales. If they won't do that, that's a red flag.

Choosing between processors

Start by deciding how you'll accept cards: in person, online, or both. That narrows your options significantly. Then get quotes from at least three processors and compare the total cost, not just the per-transaction rate. Include all monthly fees, and calculate what you'll pay on your expected monthly volume.

Ask about integration with your existing tools. If you use Shopify, Stripe integrates seamlessly. If you use QuickBooks, some processors sync automatically and some don't. If you use a point-of-sale system, check whether the processor is compatible before you commit.

Check the contract for lock-in periods and cancellation fees. Month-to-month is better than a fixed term, especially if you're new to accepting cards and aren't sure what your volume will be. Read reviews on independent sites (not the processor's own website), and ask other business owners in your industry what they use and whether they're happy.

Frequently Asked Questions

Can I use the same processor for in-person and online sales?

Yes, many processors like Square and Stripe offer both. The advantage is one contract and one rate across all your channels. The disadvantage is that if you're unhappy with one part of their service, you have to switch everything. Some businesses use different processors for in-person and online to keep their options open.

What's the difference between a processor and a payment gateway?

A payment gateway is the software that collects card information (like the form on your website). A processor is the company that moves the money. Many companies do both, which is why the terms get confused. For your purposes, they're usually the same company, so you don't need to think about them separately.

Do I have to use the processor my bank recommends?

No. Your bank can offer processing, but you can also use Square, Stripe, or any other processor. Banks sometimes have higher rates because they assume you'll stay with them for other services. Shop around before you assume the bank's offer is the best one.

What happens if a customer disputes a charge?

The processor will notify you and ask for proof that the transaction was legitimate (like a receipt or shipping confirmation). If you can't prove it, the money goes back to the customer and you're charged a chargeback fee (usually $15 to $100). Too many chargebacks can get your account closed, so keep good records of every transaction.

Can I negotiate my processing rate?

Yes, but only the processor's markup, not the interchange fee. If you process high volume or have been with a processor for years, you can ask for a lower rate. New businesses with low volume have less leverage. Getting quotes from multiple processors and mentioning competing offers sometimes works.