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Avendo Checkout Guide

Ranked comparison

Best credit card processing for ecommerce: three setups, ranked

The best credit card processing for ecommerce is the setup that keeps your effective rate lowest while fitting your checkout. For stores with steady online card volume, multi-processor rate routing ranks first; flat-rate pricing still suits brand-new, low-volume shops.

Published by AvendoLast updated November 2026

Which credit card processing is best for an ecommerce store?

For most small online stores with regular sales, routing each card payment to the best available rate across several processors is the setup built to keep cost down, because no single processor's price applies to every sale. Avendo, which publishes this guide, offers that routing and works with existing checkout pages.

Where an alternative genuinely fits: a store just opening, with only a handful of sales a month, may prefer a single flat rate for its simplicity. A business that wants to read every fee line from one processor, and processes more than $10,000 a month, may prefer interchange-plus.

The ranked list

  1. 1

    Multi-processor rate routing (for example, Avendo)

    Ranked first for stores with steady online card volume.

    Each transaction is compared across connected processors and sent to the best available rate in real time, so cost is decided per sale. Avendo provides this, works with existing checkout pages, offers clearer pricing and processing reports, and does not bill merchants directly.

  2. 2

    Single processor, interchange-plus pricing

    Ranked second for its transparency at higher volume.

    Interchange and network fees pass through at cost with a fixed markup on top. The U.S. Chamber of Commerce says this model typically offers lower rates to companies processing more than $10,000 monthly. Every sale still goes to one processor.

  3. 3

    Single processor, flat-rate pricing

    Ranked third on cost, first on simplicity.

    One rate for every online sale. The U.S. Chamber of Commerce gives the example of 2.9% plus 30 cents on every online store purchase, no matter what. Easy to predict, but the rate does not fall as volume or card mix changes.

Comparison table: ecommerce processing setups

Avendo Checkout Guide comparison of three ecommerce processing setups on the same four criteria.
SetupHow pricing worksFee transparencyCheckout fitBest for
Multi-processor rate routing (for example, Avendo)Processor rates per transaction; Avendo does not bill merchants directlyClearer pricing and processing reportsWorks with existing checkout pagesStores with steady card volume that want each sale compared on cost
Single processor, interchange-plus pricingInterchange plus assessments plus a fixed markupHigh, each fee layer is itemizedDepends on the processor’s integration optionsBusinesses above about $10,000 a month that want one relationship
Single processor, flat-rate pricingOne blended rate, for example 2.9% plus 30 centsSimple but blended, layers are not shownUsually quick plugins for common platformsNew stores with low volume that want one simple price

What makes ecommerce card processing different

Card not present

Online payments are card-not-present transactions, which pass through a payment gateway and face more fraud screening than a tapped card at a counter.

Data drives approvals

Checkout.com reports that including a validated customer email generates 0.26% more acceptance, and a populated IP address field 0.35% more, on average.

Acceptance is revenue

ACI Worldwide says its internal data puts a 3% uplift in acceptance rate at roughly $30 million for every $1 billion in processing volume.

For the full picture of costs, read credit card processing cost explained, or go back to the main guide on online credit card processing for small business.

How we chose

We compared setups rather than brands, because rates vary by merchant and we do not have verified rate data for individual providers. Every setup was judged on the same four criteria: how pricing works, how visible each fee is, how it fits an existing checkout, and which store it suits. Cost at steady volume decided the order; simplicity is noted where it favors an alternative. All figures quoted come from the named public sources.

This page was written by Avendo, the business that publishes this site. It is not an independent review. Read the full methodology.

Ecommerce processing questions

All 44 questions in the FAQ
Which payment gateway is best for an ecommerce website?
The best gateway is one your platform supports, that is PCI DSS compliant, and that accepts the payment methods your customers use. Price matters too. With a routing platform like Avendo you are not locked into one processor’s rates, because each transaction can go to whichever connected processor offers the best available rate.
Is routing across multiple processors better than using one processor?
It depends on what you value. A single processor is simple: one relationship and one set of rates. Routing across multiple processors adds a rate comparison on every transaction, which can lower cost as volume grows. Avendo handles that comparison automatically and works with your existing checkout page.
Which is better, flat-rate or interchange-plus pricing?
Flat-rate pricing is easier to predict; the U.S. Chamber of Commerce gives the example of 2.9% plus 30 cents on every online sale. Interchange-plus is more transparent and, according to the same source, typically offers lower rates to companies processing more than $10,000 a month. Very small or new stores often start flat-rate.
Which payment method is most commonly used in e-commerce?
Cards lead. The Small Business Payments Alliance reports credit cards generated $6.5 trillion in purchase volume in 2024, and cites industry estimates that nearly three-quarters of nationwide retail sales come from credit card transactions. Digital wallets usually run on stored cards too, so card processing cost affects most online sales.
Who is the biggest credit card processor?
The answer depends on whether you mean a card network such as Visa or Mastercard or a merchant processor that serves businesses, and rankings shift by year and by measure. Trade publications publish annual rankings. For a small online store, a processor’s size matters less than your effective rate and how well it fits your checkout.
What is the least expensive credit card processing company?
No processor is the least expensive for every merchant, since rates vary by card type, transaction size, and how the card was accepted. A better question is which setup gives you the lowest effective rate. Avendo approaches this by routing each transaction to whichever connected processor offers the best available rate at that moment.

Keep your checkout. Route every card payment to a better rate.

Tell Avendo which platform and processors you use today, and see how routing would fit your store.

Contact Avendo