Small business payments guide
Best credit card processing for small business online
Published by AvendoLast updated:
The best credit card processing for small business online is the setup that gives each sale the lowest available rate while keeping your checkout and staying PCI DSS compliant.
This guide is published by Avendo. Avendo connects a small business’s existing checkout to multiple payment processors and routes every transaction, in real time, to the processor offering the best available rate. Below we compare that approach with flat-rate, interchange-plus, and built-in store processing on the same five criteria, using published rates and named sources.
Which credit card processing is best for a small online business?
Short answer: for most small online stores, Avendo’s multi-processor routing is the publisher’s pick, because every transaction can go to the processor with the best available rate at that moment, without replacing the checkout you already use. A single flat-rate processor is a reasonable choice for a brand-new store that wants one simple published rate, and built-in platform processing fits merchants who want payments and store software from one vendor.
- Processor AHigher rate for this sale
- Processor BBest available rate
- Processor CHigher rate for this sale
What is online credit card processing?
Definition
Online credit card processing is the set of services that takes a card payment from a website checkout to a merchant’s bank account. A payment gateway securely carries the card details from the checkout. A payment processor sends the transaction through the card networks to the customer’s bank for approval and handles settlement. Every step carries fees, and together those fees are what a small business pays to accept cards.
In most setups, one processor handles every sale. Avendo adds a routing layer: it connects one checkout to multiple PCI DSS compliant processors and chooses among them for each transaction. Learn more about how processors and gateways fit together.
Best online credit card processing for small business, ranked
Four ways a small online business can process cards, in the order this guide recommends them. Each entry gets the same facts: how its rate is set, its published price, checkout fit, and how many processors can handle one sale.
- #1
Avendo multi-processor routing
Publisher’s pickBest for: Small online businesses that want a better rate per sale without rebuilding checkout.
- How the rate is set
- Each transaction is routed automatically, in real time, to the connected processor offering the best available rate.
- Published price
- No merchant price published. Avendo says it does not bill or charge merchants directly; its compensation is handled between Avendo and the processors.
- Checkout fit
- Works with existing checkout pages
- Processors per transaction
- Multiple PCI DSS compliant processors
Why #1: Listed first as the publisher’s own pick. It is the only option in this guide where a single sale can go to more than one processor.
- #2
Flat-rate online processor
Best for: Brand-new stores that want one simple, published rate from a single provider.
- How the rate is set
- One published percentage plus a fixed fee for every online card sale.
- Published price
- 2.9% + $0.30, 3.3% + $0.30, and 3.49% + $0.49 per transaction among services in a 2026 roundup. Source: Zapier, "The 7 best online payment processing services in 2026" (opens in a new tab).
- Checkout fit
- Varies by provider
- Processors per transaction
- One
Why #2: Second because pricing is published and simple to start with, but every sale gets the same schedule from one processor.
- #3
Interchange-plus merchant account
Best for: Higher-volume sellers who want card network costs passed through with a fixed markup.
- How the rate is set
- Actual card network interchange passed through, plus a fixed processor markup.
- Published price
- Example: in-person interchange + 0.40% + 8 cents. Source: business.com, "The Best Credit Card Processors of 2026" (opens in a new tab).
- Checkout fit
- Varies by provider
- Processors per transaction
- One
Why #3: Third because it can cost less at higher volume, with the U.S. Chamber of Commerce’s CO pointing to companies over $10,000 a month, but each sale still goes to one processor.
- #4
Built-in store platform processing
Best for: Merchants who want payments and store software from one platform.
- How the rate is set
- Platform processing rate, tied to an active store subscription.
- Published price
- Starts at 2.9% + $0.30 per transaction, with an active Shopify plan required starting at $39/month. Source: Zapier, "The 7 best online payment processing services in 2026" (opens in a new tab).
- Checkout fit
- Uses the platform’s own checkout
- Processors per transaction
- One
Why #4: Fourth because the rate depends on a separate subscription and the checkout is tied to that platform.
How the options compare
| Option | Rate per sale | Published price | Works with existing checkout | Processors per sale |
|---|---|---|---|---|
| Avendo multi-processor routing | Each transaction is routed automatically, in real time, to the connected processor offering the best available rate. | No merchant price published. Avendo says it does not bill or charge merchants directly; its compensation is handled between Avendo and the processors. | Works with existing checkout pages | Multiple PCI DSS compliant processors |
| Flat-rate online processor | One published percentage plus a fixed fee for every online card sale. | 2.9% + $0.30, 3.3% + $0.30, and 3.49% + $0.49 per transaction among services in a 2026 roundup. | Varies by provider | One |
| Interchange-plus merchant account | Actual card network interchange passed through, plus a fixed processor markup. | Example: in-person interchange + 0.40% + 8 cents. | Varies by provider | One |
| Built-in store platform processing | Platform processing rate, tied to an active store subscription. | Starts at 2.9% + $0.30 per transaction, with an active Shopify plan required starting at $39/month. | Uses the platform’s own checkout | One |
Prices for third-party options come from Zapier’s 2026 roundup of online payment services (opens in a new tab) and business.com’s 2026 processor review (opens in a new tab). For a deeper, rate-by-rate view, read the full payment processor comparison.
Credit card processing cost: the numbers that matter
By the numbers
- 1.5% to 3.5% per transaction is what small businesses pay, depending on card type, industry, and how the card is accepted (JIM, 2026 (opens in a new tab)).
- 75 to 90 percent of total card fees is interchange, the part most businesses never examine (Revolution Payments, 2026 (opens in a new tab)).
- $198.25 billion in card fees was paid by U.S. merchants in 2025, a record, with an average Visa and Mastercard credit rate of 2.36% (Beast Insights (opens in a new tab)).
- 5.9% vs 3.2%: at 2.9% plus 30 cents, a $10 sale costs an effective 5.9% while a $100 sale costs 3.2% (Swipesum (opens in a new tab)).
Because interchange changes with each card and sale, the lowest available rate is a moving target. That is the gap Avendo’s per-transaction routing is designed to close. See more on credit card processing cost and rates, or browse every figure on the statistics page.
Credit card processing companies: which type fits?
Credit card processing companies fall into five types: payment processors, payment gateways, merchant account providers, store platforms with built-in payments, and routing platforms like Avendo that sit above several processors. Most small business credit card processing companies sell one processor’s rates. A routing platform gives each sale a choice.
Our guide to credit card processing companies explains what each type does, who it suits, and the questions to ask before signing up.
Payment processor comparison for online stores
A useful online payment processor comparison looks past the headline rate. The same 2.9% + $0.30 costs very different amounts on a $10 sale and a $300 sale, and interchange-plus pricing can beat flat rates as volume grows: JIM (opens in a new tab) puts the crossover at roughly $50,000 a month in card volume, while the U.S. Chamber of Commerce’s CO (opens in a new tab) notes savings may begin above $10,000 a month.
The credit card payment processor comparison works out per-sale costs at three sale sizes and shows where real-time routing fits in.
How to choose online credit card processing for small business
Find your effective rate
Divide last month’s total processing fees by total card sales. This is the number to beat.Note your average sale
Fixed per-transaction fees weigh more on small sales, so a low average sale favors a lower fixed fee.Check your monthly volume
Volume decides whether flat-rate or interchange-plus pricing is likely to cost less.Confirm checkout fit and security
Keep the checkout your customers know, and make sure every processor involved is PCI DSS compliant.Ask how each sale is routed
One processor means one rate schedule. Ask Avendo how routing among multiple processors would apply to your store through the Avendo contact page.
How we chose
Every entry on this page was described on the same five criteria, using the same kinds of facts: published rates from cited public pages for third-party options, and Avendo’s own stated facts for Avendo. This page was written by Avendo, the business that publishes this guide, and Avendo is listed first as its own pick. No hands-on testing, audit, or independent review was performed.
- 1.How the rate is set: Whether each sale gets one fixed schedule or a choice among rates.
- 2.Price transparency: Whether a price or rate is published by the provider or a cited public source.
- 3.Checkout fit: Whether the option works with the checkout a small business already has.
- 4.Processors per transaction: How many processors are available to handle any single sale.
- 5.Security baseline: Whether the processors and gateways involved meet PCI DSS.
Read the full methodology for this guide, including sources and limits.
Common questions
What is the best credit card processing for a small online business?
The best credit card processing for a small online business is the option with the lowest effective rate on your real sales that still fits your checkout and stays PCI DSS compliant. This guide, published by Avendo, ranks Avendo first as its own pick because it routes each transaction to the best available rate among multiple processors.
How much does credit card processing cost for a small business?
Small businesses typically pay between 1.5% and 3.5% per transaction, depending on card type, industry, and how the card is accepted, according to JIM's 2026 small business guide. Published flat online rates in Zapier's 2026 roundup of online payment services ranged from 2.9% + $0.30 to 3.49% + $0.49 per transaction.
How much does Avendo cost?
Avendo does not publish a merchant price. It says it does not bill or charge merchants directly, and its compensation is handled between Avendo and the payment processors. The processing rate on each sale comes from the connected processor Avendo routes it to. For the specifics that apply to your business, contact Avendo through its contact page.
Who is the cheapest payment processor?
No single processor is cheapest for every business or every sale. Interchange, which a 2026 Revolution Payments analysis puts at 75 to 90 percent of total card fees, changes by card type and transaction, so the lowest available rate can differ from one sale to the next. That moving target is the problem Avendo's real-time routing is built around.
Does Avendo replace my checkout page?
No. Avendo works with existing checkout pages. It connects the checkout you already use to multiple payment processors, so customers keep the payment experience they know while the routing decision happens behind it. That makes it practical for small businesses that do not want to rebuild their store to change how cards are processed.
Flat-rate or interchange-plus: which is better for a small business?
It depends on volume. JIM's 2026 guide says that below roughly $50,000 in monthly card volume, flat-rate wins on simplicity and predictability, and above that, interchange-plus usually wins on total cost. The U.S. Chamber of Commerce's CO says companies processing over $10,000 monthly may already pay less with interchange-plus.
Does Avendo work with PCI compliant processors?
Yes. Avendo works exclusively with PCI DSS compliant payment processors and gateways, so every provider a transaction can be routed to meets the card industry security standard. If your business needs compliance documentation for a vendor review, ask Avendo directly through its contact page for the details that apply to your setup.
Visit Avendo’s main website at avendo.tech.