Top Payment Processing Systems: Fees, Features, and Pricing Structures Compared
Choosing a payment processor starts with how your customers pay. A retailer taking most sales at a counter needs dependable hardware and in-person acceptance. An agency or software company billing clients needs invoicing and online checkout, plus a way for clients to pay by bank transfer.
It's also a question of what happens after the sale. Processors pay out on different schedules and handle refunds and disputes differently. They also vary in how much transaction detail they pass to your accounting software. Those differences determine how quickly revenue reaches your bank account and how long it takes to match deposits to invoices.
This guide covers how a card payment moves from the customer's bank to yours and how processor pricing works. We compare six of the leading payment processors available to businesses today, including Slash. Slash payment processing lets approved businesses accept card payments on invoices or through a custom checkout, with funds landing in the same Slash account they use for banking and spend.¹
Slash business banking
Works with cards, crypto, plus cards, crypto, accounting, and more.
What is a Payment Processing System?
A payment processing system is the chain of software, networks, and financial institutions that moves money from a customer's card or bank account into a business's account. When a customer taps a card or enters details at checkout, the system confirms the card is valid, checks that funds or credit are available, screens for fraud, and routes the approved payment toward settlement.
Most card payments don’t just interact with a processor on route to a business’s bank account. They move through a series of different stages, which involve:
- Payment gateway: Software that captures and encrypts payment details at checkout, a card reader, or an invoice link.
- Payment processor: The company that moves transaction data between the gateway, card networks, and banks, then returns an approval or decline.
- Acquiring bank: The bank that holds the merchant relationship and receives funds for approved transactions.
- Card networks: Visa, Mastercard, American Express, and Discover, which set transaction rules and interchange fees.
- Issuing bank: The customer's bank, which approves or declines the charge.
- Merchant account: Where card proceeds land before payout to the business's bank account. Payment facilitators let businesses process under the provider's master merchant account instead of opening their own.
Types of Payment Processing Systems
Payment processing systems differ in how businesses sign up, who they're built to serve, and how they connect to a checkout. Understanding these differences makes it easier to narrow down which providers fit the way your business takes payments.
Traditional vs. digital payment processing
Traditional payment processing usually involves opening a dedicated merchant account opened through a bank or an independent sales organization and implementing a countertop terminal. Pricing is often negotiated, and underwriting (the provider's review of your business's risk profile before it agrees to process for you) can take days or weeks. For established, high-volume businesses, rates can be lower.
Digital processors like Slash, Square, and PayPal changed that model. Most operate as payment facilitators, so a new business can often start accepting payments within a day, usually on flat, published rates with no long-term contract. The tradeoff is lighter underwriting up front: if a provider later sees unusual activity, it can hold payouts or keep a reserve (a portion of your proceeds set aside to cover refunds and disputes).
B2B payment processing vs. B2C payment processing
B2C (business-to-consumer) payments tend to be high volume and low value: many card transactions for tens or hundreds of dollars, taken through an online checkout or a point-of-sale terminal. Checkout speed, mobile wallets, and fraud screening matter most.
B2B (business-to-business) payments are usually fewer and larger, and they often start with an invoice rather than a checkout page. Buyers may pay on net-30 or net-60 terms (due 30 or 60 days after the invoice date) and frequently prefer ACH or wire transfers to avoid card fees. When B2B buyers do pay by card, they often use commercial or corporate cards, which typically carry higher interchange fees than consumer debit cards. B2B sellers usually need good invoicing and bank transfer support more than a polished shopping cart.
Payment gateway integrations
A payment gateway connects the place where customers pay to the processor behind it. The integration method determines how much control you have over checkout and how much technical work you take on:
- Hosted payment pages: The customer pays on a page run by the provider. It's the quickest setup, and because the provider handles card data, it can reduce your PCI DSS scope (the Payment Card Industry Data Security Standard, the security rules for any business handling card data).
- Plugins and native integrations: Prebuilt connections for platforms like Shopify and WooCommerce, usually set up without code.
- APIs and SDKs: Code libraries for building a custom checkout inside your own site or app, with full control in exchange for engineering time. With the Slash SDK, businesses can build a checkout that looks and works like the rest of their site.
Evaluating Payment Processing Fees
The cost of processing a credit card transaction is multilayered. Interchange is the fee paid to the customer's card-issuing bank, with rates set by the card networks. It varies by card type (debit, rewards credit, commercial), how the card is taken (in person or online), and the merchant's industry. Network fees, sometimes called scheme or assessment fees, go to Visa, Mastercard, and the other networks. The processor's markup is what the provider keeps for its service.
Providers may also charge monthly subscription fees, dispute fees, international and currency conversion surcharges, instant payout fees, and hardware costs.
How to analyze and compare transaction fees
Most processors use one of three pricing models:
- Flat-rate: One blended rate, such as 2.9% plus 30 cents. Predictable, but you pay the same on a low-cost debit card as on a premium rewards card.
- Interchange-plus: You pay the actual interchange and network fees for each transaction, plus a fixed markup from the processor. Costs vary more month to month, but this model can be cheaper at higher volumes.
- Tiered: Transactions are sorted into rate buckets (often qualified, mid-qualified, and non-qualified). Usually the least transparent, since the provider decides which bucket applies.
To compare payment processing providers, calculate your effective rate, which is total processing fees for a month divided by total card volume. Take $50,000 in monthly card sales at 2.9% plus 30 cents. If that volume comes from 1,000 transactions averaging $50, fees total $1,750, an effective rate of 3.5%. If it comes from 500 transactions averaging $100, fees total $1,600, or 3.2%. The only variable is transaction size.
Hidden costs to consider
Not every processing cost shows up in the per-transaction rate. Watch for:
- Contract terms: Multi-year agreements with early termination fees.
- Monthly minimums: Some providers bill a minimum amount if your fees fall below a threshold.
- Reserves and payout holds: Not a fee, but a real cash flow cost.
- PCI compliance fees: Charges for compliance programs, or penalties for skipping required security questionnaires.
- Refund treatment: Some processors keep part or all of the original fee when you refund a sale.
- Equipment leases: Often far more expensive over the term than buying a terminal outright.
The standard in finance
Slash goes above with better controls, better rewards, and better support for your business.
The Top 6 Payment Processing Systems in 2026
The rates below are standard published U.S. rates as of September 2026. Processors change pricing regularly, and many negotiate custom rates for higher-volume businesses, so confirm current terms directly with each provider.
Slash
Slash lets approved businesses accept card payments straight into their business banking account. Accept cards on Slash invoices or build a custom checkout with the Slash SDK. The Payment Processing dashboard tracks gross and net volume, available and pending balances, refund rates, and chargebacks, and payouts and disputes are managed in the same place. It also functions as a merchant of record (MoR), meaning Slash is the legal seller on the transaction and holds the underlying processing relationships. Most MoRs charge between 4-6% plus change per transaction, while Slash’s fee is only 3% plus 40 cents.
- Pricing model: Flat-rate
- Published U.S. rate: 3% plus 40 cents per transaction
- Monthly fee: $0 to $25 for Slash Pro
- Best for: Businesses in e-commerce, telehealth, software, and service agencies (marketing, advertising, consulting)
- Payment methods: Visa, Mastercard, American Express, Discover, JCB, Diners Club, and more
- Notable requirement: Approval required, and the business banks with Slash
Stripe
Stripe is built for online businesses with developers to work with. Its APIs are widely used by SaaS companies and marketplaces, with paid add-ons for subscriptions, sales tax, and fraud screening.
- Pricing model: Flat-rate by default, with custom and interchange-plus pricing available for larger businesses
- Published U.S. rate: 2.9% plus 30 cents for domestic online card payments, and 2.7% plus 5 cents for in-person payments through Stripe Terminal
- Monthly fee: None on the standard plan
- Best for: Online businesses, SaaS, and platforms with engineering resources
- Additional fees: International cards add 1.5%, currency conversion adds 1%, and disputes cost $15
Adyen
Adyen serves large, often multinational merchants that want online and in-person payments on one platform, with broad support for local payment methods.
- Pricing model: A fixed processing fee per transaction plus a payment method fee; for cards, that's interchange-plus (Adyen calls it Interchange++)
- Published U.S. rate: Not a flat rate; varies by payment method
- Monthly fee: No setup or monthly fees, though Adyen applies a minimum invoice that depends on industry and business model
- Best for: Enterprise and high-volume businesses selling across multiple countries
- Notable requirement: Selective onboarding, with pricing and eligibility handled through a sales conversation
Global Payments
Global Payments completed its acquisition of Worldpay in January 2026 and sold its card issuer business to FIS, making it a company focused entirely on merchant payments. Its Genius point-of-sale platform targets restaurants and retailers.
- Pricing model: Quote-based, typically negotiated per business
- Published U.S. rate: Not published
- Monthly fee: Varies by contract
- Best for: Restaurants, retailers, and established businesses that want processing and point-of-sale software from one provider
- Notable requirement: Contract terms vary, so review term length and any early termination fees before signing
PayPal
PayPal's main draw is buyer recognition. Many shoppers already have a PayPal or Venmo account, and a familiar button can help some sellers convert hesitant customers.
- Pricing model: Flat-rate, varying by payment method and checkout product
- Published U.S. rate: 3.49% plus 49 cents for PayPal and Venmo payments, 2.99% plus 49 cents for card payments through PayPal Checkout, with lower rates on its developer-integrated checkout
- Monthly fee: None on a standard account
- Best for: Online sellers whose customers expect a PayPal option at checkout
- Additional fees: International transactions add 1.5%
Square
Square pairs processing with point-of-sale software and hardware, which has made it a common choice for small in-person businesses. It raised several standard rates in 2026, so older comparisons may be out of date.
- Pricing model: Flat-rate, with lower rates on paid plans
- Published U.S. rate (Free plan): 2.6% plus 15 cents in person, 3.3% plus 30 cents online, and 3.5% plus 15 cents for keyed-in or card-on-file payments
- Monthly fee: $0 on the Free plan, $49 per location on Square Plus, and $149 per location on Square Premium (paid plans lower some rates)
- Best for: Retail shops, restaurants, and service businesses that take most payments in person
Choosing the Right Payment Processing System for Your Business
The right processor has less to do with finding the lowest rate than with how well it fits the way your business sells and operates. These five factors will help you narrow the options before you compare quotes.
Determine how your customers pay
Most processors price in-person, online, and invoice payments differently. A business that takes most payments at a counter should weigh in-person rates and hardware, while one that sells online or invoices clients should focus on online rates and whether customers can pay by ACH.
Look at transaction size and volume
A coffee shop with $8 average sales feels every cent of a fixed per-transaction fee, while an agency collecting $5,000 invoices cares more about the percentage rate. Flat-rate pricing is usually simpler at lower volumes, while interchange-plus often gets cheaper as volume grows.
Decide your mobile payment needs
Phone-connected card readers and tap-to-pay let businesses selling at events or on-site take payments anywhere for little upfront cost, and mobile wallets use tokenization (replacing the real card number with a one-time code) that can reduce fraud exposure. The tradeoff is dependence on battery and connectivity, and offline payments carry risk because a card can't be authorized until the device reconnects.
Consider integration with existing systems and software
Processors typically pay out in batches with fees already deducted, so ask whether a provider sends transaction and fee detail to your accounting software. Otherwise, matching deposits to invoices can eat hours at month-end. Payments processed through Slash land in the Slash account already tied to their invoices, and Slash syncs with QuickBooks Online, Xero, NetSuite, and Sage Intacct.
Evaluate payouts, support, and eligibility
Check how quickly payouts arrive, whether faster payouts cost extra, and what support looks like when a dispute comes in. Also confirm the provider accepts your industry, since some processors decline categories they consider higher risk.
Get Paid With Slash
If you invoice clients or sell online, Slash gives you two ways to accept cards. Turn on card payments when you send a Slash invoice, and clients can pay by Visa, Mastercard, American Express, Apple Pay, or Google Pay. Or use the Slash SDK to build card payments into your own website, with full control over what customers see at checkout.
Once a payment settles, it lands in your Slash business account, ready to use. Pay your Slash corporate card with it, where eligible purchases can earn valuable cashback, or move your extra cash into Slash Treasury to earn yield.⁶ Applying can take less than 10 minutes.
Since our Payment Processing product functions as a merchant of record, you don't have to apply for, set up, or manage merchant identification numbers, and you won't need a separate merchant account. That said, while some MoRs handle sales tax for you, Slash does not.
Here’s what else you get with Slash:
- Slash Visa Platinum Card: Corporate charge cards that can earn up to 2% cash back with granular spend controls, spend limits, and card grouping.
- Business banking: FDIC-insured business checking, protected up to $150M through Column N.A.'s insured cash sweep network.²
- Multiple payment methods: Send and receive funds via same-day ACH, wires on SWIFT to 180+ countries, RTP, FedNow, and stablecoin transfers in USDC or USDT.⁴
- Accounts payable and receivable: Create invoices, track payment status, and collect payments via multiple methods all in your dashboard. For your bills, Slash can parse an uploaded invoice, route each bill for approval, and track its status from pending to paid, so payables don't slip through the cracks.
- Integrated treasury: High-yield treasury accounts earning up to 3.86% annualized yield backed by Morgan Stanley and BlackRock money market funds, with no minimum balance to get started.
- Flexible financing: Access to a line of credit in your Slash dashboard to support cash flow gaps or temporary funding, with 30, 60, or 90 days repayment terms.⁵
Apply in less than 10 minutes today
Join the 10,000+ businesses already using Slash.
Frequently Asked Questions
What is the best way for a small business to accept payments?
It depends on how customers pay and how large each sale is. In-person card payments usually cost less than online or keyed-in payments, and for large invoices, ACH transfers are often far cheaper than cards. As volume grows, interchange-plus pricing may lower costs compared to a flat rate.
The Top Credit Card Processors for Small Businesses Compared
How long does it take to get paid by a payment processor?
Standard payouts often arrive in one to two business days, though timing varies by provider and account. Many processors offer instant or same-day payouts for an extra fee. New accounts may start on a longer payout schedule until the provider has more history with the business.
What is a chargeback, and how much does it cost a business?
A chargeback happens when a customer disputes a card charge with their bank and the bank reverses the payment while it investigates. The business loses the sale amount during the dispute and often pays a separate dispute fee, which some processors refund if you win. A high chargeback rate can also lead a processor to add reserves or close the account.
Chargeback Prevention: 6 Ways to Protect Revenue and Reduce Risk
