What a credit card processor does, and why you need one
A credit card processor is the company that moves money from your customer's card to your bank account. When someone hands you a card or enters their number online, the processor talks to the card network (Visa, Mastercard, American Express), checks that the card is real and has funds, and either approves or declines the transaction. Without a processor, you cannot accept cards at all.
You do not deal with Visa or Mastercard directly — they set the rules, but the processor is your actual vendor. The processor charges you a fee (usually a percentage of each sale plus a small flat fee), handles the technical side, and deposits money into your business bank account, typically within one to three business days.
Most small businesses use a processor because cards now account for the majority of retail and online sales. Customers expect to pay with plastic, and the fee you pay is usually less than the profit you make on the sale. The processor also handles fraud detection, dispute resolution, and the paperwork that keeps you compliant with card network rules.
Key Takeaways
- A processor is a separate company from your bank — your bank holds your money, but the processor moves the customer's card payment into your account.
- Fees vary widely by processor and by how you accept cards (in-person, online, phone, mail), so comparing the actual cost of three to five processors is worth an hour of your time.
- Interchange fees (set by card networks, not the processor) are the largest cost and are the same everywhere, but processor markups and monthly charges vary significantly.
- In-person payment devices (card readers that plug into a phone or tablet) are usually free or cheap from the processor, but online payment forms and phone-line processing have different fee structures.
- Your processor must integrate with your point-of-sale system or accounting software, so check compatibility before signing up.
How processor fees actually work
Card processing fees have three layers, and understanding the difference matters because you can only control one of them. Interchange is the fee the card network (Visa, Mastercard) charges the processor, and it is the same no matter which processor you use — it varies by card type (debit, credit, rewards card) and typically ranges from about 1.5% to 2.5% of the sale. The processor cannot lower this, and neither can you.
On top of interchange, the processor adds its own markup — this is where prices differ. One processor might add 0.3% plus $0.10 per transaction, while another adds 0.5% plus $0.25. Over hundreds of transactions, this difference adds up. Some processors also charge a monthly fee (often $10 to $30) whether you process any cards or not.
A few processors offer interchange-plus pricing, which means they show you the interchange fee separately and charge you a flat markup on top (for example, "interchange plus 0.5%"). This is usually the most transparent option, though not always the cheapest. Most small businesses see total fees between 2.2% and 3.5% per transaction, depending on the processor and the type of card used.
In-person, online, and phone processing — which one you need
The way you accept cards changes which processor makes sense. In-person processing uses a physical card reader — either a small device that plugs into your phone or tablet (like Square or Toast), or a traditional countertop terminal. These are usually the cheapest option because the processor can verify the card is real right there. Fees are typically 2.6% to 3% per transaction, and the device itself is often free or costs $20 to $100 one time.
Online processing (for e-commerce) uses a payment form on your website or a hosted checkout page. Because the customer is not physically present, the processor charges slightly more to cover fraud risk — usually 2.9% plus $0.30 per transaction, or a flat percentage. You will also need an SSL certificate (encryption) on your website, which most processors help you set up.
Phone and mail processing is the most expensive because the processor cannot verify the card in real time. You read the card number over the phone or from a check, and the processor has to trust you entered it correctly. Fees often run 3.5% to 4% per transaction. If you only take a handful of phone orders a month, this might be acceptable; if it is your main channel, consider switching to online or in-person.
Comparing processors: what to check before you sign up
Start by listing how you actually take payments. Do you have a physical store? Do you sell online? Do you take phone orders? Do you need to invoice customers? The answer determines which processors are even relevant — some are built for retail only, others for online only, and a few handle both.
Next, check whether the processor works with your point-of-sale system (the cash register software you use) or your accounting software (QuickBooks, Xero, FreshBooks). If your POS or accounting system has a list of approved processors, start there — the integration is already built and tested. If you do not have a POS system yet, some processors (like Square, Toast, Clover) include one for free or a low monthly fee.
Then get a quote from at least three processors. Tell them your monthly card volume (total dollars, not number of transactions) and the mix of card types you accept (mostly credit cards, some debit, some rewards cards). Ask for the all-in cost per transaction, any monthly fees, and the timeline for deposits to your bank account. Write down the answers side by side — the cheapest is not always the best, but you should understand why you are paying more.
Finally, check the contract terms. Some processors lock you in for two years; others month-to-month. Some charge an early termination fee if you leave before the contract ends. Read the fine print or call and ask — a processor that is confident in its service will not bury the terms.
Popular processors and what they are built for
Square is designed for small retail and service businesses. You get a free card reader that plugs into your phone, and you pay 2.6% plus $0.10 per transaction for in-person cards. Online payments cost 2.9% plus $0.30. Square also offers a free point-of-sale system and invoicing. The downside is that fees are higher than some competitors, and there is no monthly fee to waive them.
Stripe is built for online businesses and developers. Fees are 2.9% plus $0.30 per online transaction, with no monthly fee. Stripe integrates with hundreds of shopping carts and accounting tools. In-person processing is available but requires a separate device and higher fees. Stripe is not ideal if you only take in-person payments.
Toast is designed for restaurants and hospitality. It includes a full point-of-sale system, kitchen display screens, and staff management. Processing fees are 2.6% plus $0.10 for in-person cards. The POS system costs $69 to $99 per month, so Toast is more expensive upfront but handles the whole operation in one place.
Clover (owned by Fiserv) is a general-purpose processor with a free point-of-sale system. In-person fees are 2.7% plus $0.10, and online fees are 2.9% plus $0.30. Clover works well for retail, restaurants, and service businesses. The free POS system is a major advantage if you do not already have one.
PayPal and Authorize.Net are older, established processors. PayPal charges 2.9% plus $0.30 for online payments and 2.7% plus $0.10 for in-person (with their card reader). Authorize.Net is primarily for online and phone processing and is often used by larger or more technical businesses. Both have lower fees than Square in some scenarios, but fewer built-in tools.
Questions to ask before you commit
Call or email the processor and ask these questions. The answers will tell you whether they are a good fit and whether they are being straight with you.
What is the total cost per transaction for my mix of cards? Do not accept a percentage alone — ask them to calculate the fee on a $100 sale with a typical credit card. This gives you a real number to compare.
Are there any monthly fees, annual fees, or setup fees? Some processors waive monthly fees if you process a certain amount per month. Ask what the threshold is.
How long does it take for money to hit my bank account? Most say one to three business days, but some charge extra for next-day deposits. Ask whether weekends and holidays affect the timeline.
What happens if I want to leave? Ask about the contract length, early termination fees, and the process for switching. A processor that makes it straightforward to leave is usually confident in its service.
Do you integrate with my POS or accounting software? If you already use QuickBooks or a specific cash register system, confirm the integration is built in and does not require a third-party tool.
Getting started: the signup process
Once you have chosen a processor, you will need to provide business information: your legal business name, address, tax ID (EIN), and the names and Social Security numbers of the owners. The processor uses this to verify you are a real business and to comply with banking regulations.
You will also need a business bank account. The processor will deposit money into this account, so have the account number and routing number ready. If you do not have a business bank account yet, open one before you sign up with a processor — it takes a few days and makes everything cleaner.
The processor will ask you to agree to their terms of service, which include the fee structure, dispute resolution process, and rules about what you can and cannot sell. Read this carefully or have someone read it with you — it is a contract, and you are responsible for following it.
After you submit your information, the processor will review it (usually within one to three business days) and either approve you or ask for more information. Once approved, you can start processing cards when ready. If you ordered a physical card reader, it will arrive in the mail within a week or two.
Frequently Asked Questions
Can I use the same processor for both in-person and online payments?
Yes, most major processors handle both. However, fees differ — in-person is usually cheaper because the card is verified in real time. Some processors charge the same rate for both, which means you are overpaying on in-person. Ask for separate quotes for each method before you sign up.
What if a customer disputes a charge or claims fraud?
The processor handles the dispute process. You will be asked to provide proof that the transaction was legitimate (receipt, shipping confirmation, email correspondence). If you cannot prove it, the processor refunds the customer and you lose the money. This is why keeping records and using clear business names on statements matters.
Do I have to use the processor's point-of-sale system?
No. You can use any POS system that integrates with your processor, or you can use a standalone POS and connect it to the processor. However, some processors (like Square and Clover) offer free or cheap POS systems, which can save you money if you do not already have one.
What is the difference between a processor and a payment gateway?
A processor moves the money; a gateway is the software that takes the customer's card information and sends it to the processor. For in-person payments, the card reader is both. For online payments, you might use Stripe (which is both) or Authorize.Net (gateway) connected to a separate processor. Most small businesses do not need to think about this distinction — the processor you choose will handle it.
Can I switch processors if I am unhappy?
Yes, but check your contract first. Month-to-month contracts let you leave anytime. Multi-year contracts may charge an early termination fee. The switching process itself is straightforward — your new processor will help you move your customer information and settings. Plan for a few days of overlap while you test the new system.