What a payment processor actually does
A payment processor is a company that moves money from your customer's bank account or card to your business bank account. When someone swipes a card or enters their payment details online, the processor is the middleman handling that transaction — checking that the card is real, that the account has funds, and that the payment goes through safely.
You might think your bank does this work, but usually it doesn't. Your bank holds your money once it arrives, but the processor is what makes the arrival happen. A processor takes the payment information, sends it to the customer's bank to verify, gets approval or denial, and then tells your point-of-sale system (the register, the website, the app) whether the transaction succeeded.
Different processors charge different fees, connect to different types of businesses, and offer different tools. That's why a coffee shop, an online store, and a medical office might each use a different processor — even though they're all just trying to take payments.
Key Takeaways
- A payment processor is the company that moves money from a customer's card or bank account to your business account, separate from your own bank.
- Different processors charge different fees (usually a percentage of each sale plus a flat fee per transaction), so comparing them matters if you process many payments.
- Some processors specialize in certain types of business — online stores, restaurants, nonprofits — and offer tools built for those industries.
- Most small businesses use one main processor, but larger businesses sometimes use multiple processors to handle different payment types or reduce risk if one processor goes down.
- The processor you choose affects how fast you get paid, what payment methods you can accept, and how much you pay in fees.
Why businesses use more than one processor
Most small businesses use a single processor and never think about it again. But larger businesses, high-risk industries, and businesses that sell in multiple ways often use two or more processors at the same time.
The most common reason is payment method specialization. Some processors are built for card payments only. Others handle bank transfers, digital wallets (like Apple Pay or Google Pay), or international payments. If your business needs to accept all of these, you might use one processor for cards and another for bank transfers.
A second reason is redundancy — having a backup. If your main processor has a technical failure or freezes your account, you can switch to a second processor without losing the ability to take payments. This matters most for businesses that can't afford even a few hours without payment processing.
A third reason is cost reduction. Different processors charge different rates depending on the type of transaction. A business that processes many high-value international payments might use one processor for those (which charges lower rates on international sales) and a different processor for everyday domestic sales.
How fees differ between processors
Payment processors make money by charging you a fee on each transaction. The fee structure varies, and understanding it matters because small differences add up quickly.
Most processors charge a percentage of the sale plus a flat per-transaction fee. For example, one processor might charge 2.9% plus $0.30 per transaction, while another charges 2.2% plus $0.30. On a $100 sale, the first costs $3.20 and the second costs $2.50 — a difference of $0.70 per transaction. If you process 1,000 transactions a month, that's $700 a month in difference.
Some processors also charge monthly fees (a flat amount you pay whether you process one transaction or a thousand), setup fees (a one-time charge to start), or gateway fees (a charge for the software that connects your website or register to the processor). A few processors charge no monthly fee but higher per-transaction rates.
The rate you pay also depends on your risk level. A business with a history of chargebacks (customers disputing charges) pays higher rates than a business with a clean record. A business in a high-risk industry — like online gambling or cryptocurrency — might pay double or triple the standard rate, or might not be able to use certain processors at all.
The difference between payment processors and payment gateways
These terms are often used interchangeably, but they're technically different, and it matters if you're shopping around.
A payment gateway is the software that collects payment information — the form on your website, the card reader at your register, the app on your phone. It's what the customer sees and interacts with.
A payment processor is the company that takes that information and actually moves the money. The gateway sends the data to the processor, the processor talks to the customer's bank, and the processor sends the result back to the gateway.
In practice, many companies offer both. Square, for example, provides the card reader (gateway) and processes the payment (processor) as one service. But some businesses use a gateway from one company and a processor from another — for example, using Shopify's gateway with Stripe as the processor. This separation gives you more flexibility but also more complexity.
Common processors and what they're built for
Stripe is built for online businesses and software companies. It's popular with e-commerce stores, SaaS companies, and marketplaces. Stripe handles card payments, bank transfers, and digital wallets, and it's designed for developers who want to customize how payments work.
Square is built for in-person businesses — restaurants, retail shops, salons. It offers card readers that plug into phones or tablets, and it includes point-of-sale software. Square also handles online payments and has tools for invoicing.
PayPal (which owns Braintree) handles both in-person and online payments. It's familiar to consumers because many people have PayPal accounts, so some customers prefer paying through it. PayPal charges higher fees than some competitors but offers strong fraud protection.
Authorize.Net is one of the oldest processors and is popular with traditional businesses — plumbers, contractors, medical offices. It's less flashy than newer processors but reliable and widely integrated with accounting software.
Toast and Toast Go are built specifically for restaurants and bars. They include menu management, kitchen display systems, and inventory tracking alongside payment processing.
How to choose between processors for your situation
Start by identifying what you actually need to process. Do you take payments in person, online, or both? Do you need to accept international payments? Do you invoice customers and need them to pay later, or do you need when ready payment at the point of sale?
Next, calculate your expected transaction volume and average transaction size. Use this to compare fees across processors. A processor with a $20 monthly fee but low per-transaction rates might be cheaper for a high-volume business, while a processor with no monthly fee but higher per-transaction rates might be cheaper for a business that processes only a few payments a month.
Then check what payment methods each processor accepts. If you need to accept digital wallets, bank transfers, or international cards, not all processors support these equally. Read the fine print on what's included and what costs extra.
Finally, read reviews from businesses like yours. A processor that works well for an online store might be frustrating for a restaurant, and vice versa. Look for reviews that mention the specific features you need — customer support, integration with your accounting software, speed of payouts, or ease of use.
When you might need to switch processors
You don't need to switch just because another processor has a slightly lower rate. Switching costs time and carries risk — you might have downtime, you might lose transaction history, and you have to update payment information everywhere you've listed it.
You should consider switching if your fees have become significantly higher than the market rate for your business type, if your processor stops supporting a payment method you need, if you're regularly frustrated with customer support, or if you've outgrown the processor's features.
If you do switch, set up the new processor and test it thoroughly before turning off the old one. Keep both running in parallel for at least a week so you catch any problems before your old processor is gone. Update your website, invoices, and any other places where payment information appears.
Frequently Asked Questions
Can I use two processors at the same time?
Yes. Many businesses use one processor for online payments and another for in-person payments, or one for domestic transactions and another for international. You'll receive separate reports and payouts from each, so you'll need to reconcile them in your accounting. Most payment gateways (like Shopify) allow you to connect multiple processors.
Why do some processors hold my money for a while before paying me?
Processors hold money (called a "reserve") to protect themselves against chargebacks and fraud. A new business or a business in a high-risk industry might have a 7-day to 30-day hold. Established businesses with clean records usually get paid within 1 to 2 business days. Ask your processor what their payout schedule is before you sign up.
What's the difference between a discount rate and an interchange fee?
An interchange fee is what the card networks (Visa, Mastercard) charge — this is set by the networks and the same for all processors. Your processor's discount rate is what they charge on top of that. When you see a processor's advertised rate, it usually includes both. Ask them to break down the interchange fee and their markup separately so you understand what you're actually paying.
Do I need a merchant account to use a payment processor?
Most modern processors handle this for you — you don't need to set up a separate merchant account. But some traditional processors (like Authorize.Net) require you to open a merchant account with a bank first. Ask the processor whether they handle this or whether you need to do it separately.
What happens if a customer disputes a charge?
The customer contacts their bank and claims the charge was unauthorized or the product wasn't delivered. The processor notifies you, and you have a window (usually 7 to 10 days) to provide evidence that the transaction was legitimate — a receipt, shipping confirmation, or email from the customer. If you don't respond or the evidence is weak, the processor refunds the customer and charges you a chargeback fee (usually $15 to $100). Too many chargebacks can get you flagged as high-risk.