A payment processor for ecommerce is the third-party service that authorizes and settles card and ACH payments on an online store at scale.
For most small businesses selling online in 2026, the answer is Stripe or PayPal Commerce, with Square Online as a viable third option for stores that also have a physical counter.
Shopify Payments (powered by Stripe) is the canonical choice for Shopify stores; WooCommerce’s standard setup pairs with Stripe via the Stripe Payment Gateway plugin.
Run a quick stress-test: ecommerce payments differ from in-person payments in three measurable ways: chargeback rate (CNP card-not-present is materially higher than CP card-present, 0.7%-0.9% chargeback rate online vs 0.1%-0.2% in-person), international mix (online stores typically serve a higher share of cross-border customers), and subscription support (SaaS, memberships, consumables often require recurring billing).
Each difference favors a different processor: Stripe leads on API/subscription/international, PayPal leads on consumer trust at checkout, Square leads on in-person parity.
For ecommerce in 2026, the default is Stripe (best API, best subscription, best international). Add PayPal as a secondary checkout button for the consumer-trust lift. Skip Square unless you also have a physical counter. The single most important decision is to use the in-platform gateway (Stripe Checkout, Shopify Payments) over a third-party gateway (Authorize.Net + legacy processor).
Key facts: Stripe Standard is 2.9% + 30 cents on online transactions with the same rate on subscriptions and international cards +1.5%.
Square is 2.9% + 30 cents online; 2.6% + 10 cents in-person.
PayPal Commerce is 2.99% + 49 cents online.
Chargeback fee is $15 on Stripe and Square; $20 on PayPal.
Subscription billing is full-featured on Stripe Billing, limited on Square Subscriptions, basic on PayPal Subscriptions.
For a small ecommerce business processing $30,000/month with 15% international and 20% subscription: Stripe at 2.9% + 30 cents + 1.5% international + Stripe Billing at 8 cents/sub = about $980/month in fees.
PayPal Commerce at 2.99% + 49 cents + 1.5% international = about $1,050/month.
Square Online at 2.9% + 30 cents + 1.5% international = about $980/month.
The biggest factor: which one your stack integrates with.
What ecommerce payments look different from in-person
Ecommerce and in-person payments are processed by the same networks but the practical differences matter for the daily operations.
Chargeback rate is materially higher on card-not-present (CNP) transactions. The most common chargeback reason online is “I didn’t authorize this” because the customer claims they never made the purchase or that their card was stolen.
Card-present chip-and-PIN transactions drop chargeback rate by orders of magnitude because the chip cryptographically authenticates the card.
Expect CNP chargeback rate 0.7%-0.9%; CP rate 0.1%-0.2%.
The dispute process is identical; the volume is what changes.
International cards add a cross-border surcharge. A US ecommerce store selling to EU buyers sees a +1.5% surcharge on EU-issued cards. Factor into pricing for international markets; some stores price up to absorb.
Subscription support is essential for SaaS and consumables stores. Stripe Billing is full-featured: prorated charges, dunning workflows, revenue recognition webhooks, multi-currency subscription prices. Square Subscriptions is limited (basic recurring billing without dunning or revenue recognition). PayPal Subscriptions is basic (recurring billing, basic subscription management UI).
Stripe on WooCommerce and Shopify
Stripe is the canonical processor for both WooCommerce (self-hosted) and Shopify (hosted) ecommerce. The integration is a one-click plugin install for both platforms.
WooCommerce + Stripe. Install the WooCommerce Stripe Payment Gateway plugin (free, in the WordPress repository).
Configure with the Stripe publishable key and secret key from the Stripe Dashboard.
The plugin supports Apple Pay, Google Pay, ACH debit, SEPA debit, SEPA Credit Transfer, iDEAL, SOFORT, and 35+ payment methods.
Subscriptions use the WooCommerce Subscriptions plugin ($199/year per site); Stripe Billing is the underlying processor and provides the dunning and revenue recognition.
Shopify + Shopify Payments. Shopify Payments is a Stripe-powered processor native to the Shopify platform.
Setup is in the Shopify Admin (Settings -> Payments -> Shopify Payments); no plugin install.
The processor charges 2.9% + 30 cents on Shopify Basic, 2.7% + 30 cents on Shopify, and 2.4% + 30 cents on Shopify Advanced.
The rate drops with Shopify’s $39/$105/$399/month subscription tier.
Shopify handles PCI compliance scope down to SAQ-A.
Subscription support. For Shopify stores with subscriptions, Shopify Subscriptions app ($0 up to first paid tier; $24/month for Shopify Subscriptions App Pro). Stripe Billing is the underlying engine. For WooCommerce + subscriptions, the WooCommerce Subscriptions plugin handles the product config; the Stripe plugin handles the recurring charges.
Square Online: when it fits ecommerce
Square Online is Square’s ecommerce platform, free with any Square account. The platform is best for stores that also have a physical counter where Square POS is the in-person processor. Square Online’s strength is the unified inventory between Square POS and online store.
Setup time: same-day for an existing Square account. Less customizable than Shopify or WooCommerce; a clean fit for stores that prioritize unified inventory over visual customization.
PayPal integration available. Square Online + PayPal Checkout button is a supported pair; useful for the consumer-trust lift when the buyer persona gravitates toward PayPal.
Subscriptions supported but limited. Square Online supports basic recurring billing (fixed-interval subscriptions, fixed-amount) but lacks the dunning, revenue recognition, and usage-based billing of Stripe Billing.
PayPal Commerce on ecommerce: when to add it
PayPal Commerce is the canonical consumer-trust add-on. For ecommerce stores where the buyer persona is broad or international, PayPal at checkout can lift conversion 5%-15%.
WooCommerce + PayPal. WooCommerce PayPal Payments plugin (free) supports PayPal Checkout, PayPal Pay Later (4 installments), Venmo (US-only), Pay with GPay, and Pay with Apple Pay (via the PayPal gateway). The plugin is mature and one-click install.
Shopify + PayPal. Shopify has built-in PayPal Payments integration. Setup is in Shopify Admin (Settings -> Payments -> PayPal); a PayPal business account is required. PayPal Pay Later (Pay In 4) is included.
Conversion impact varies by buyer persona. PayPal’s consumer wallet recognition helps most on broad-shopper ecommerce (apparel, home goods, electronics, gifts). Helps least on developer-driven checkout (where the buyer trusts the form fields). Helps more on international (EU, AU, US expat) than domestic-only.
Subscription billing with Stripe Billing
Stripe Billing is the canonical subscription billing engine for SaaS, memberships, and consumables. Most small businesses use a single Stripe account for both one-time ecommerce orders and subscriptions.
Setup: Stripe Dashboard -> Billing -> Products. Define the product, the price (recurring interval, currency, amount), the trial period, and any usage-based pricing tier. Wire the customer’s card via Stripe Checkout for subscription sign-up. The recurring charge happens on the interval without further developer work.
Dunning workflows: Stripe Smart Retries. When a customer’s recurring charge fails (insufficient funds, expired card), Stripe Smart Retries retries the charge at the statistically optimal times in the next few days. Smart Retries recover ~50% of failed recurring charges that would otherwise be lost.
Revenue recognition: Stripe Revenue Recognition. Stripe’s native GAAP-compliant revenue recognition module posts each subscription’s revenue to a customizable accounting chart. For SaaS businesses that need monthly revenue journals, this saves hours of manual work.
Chargebacks on ecommerce: the operational discipline
Chargebacks are higher online than in-person. The operational discipline matters.
Fraud monitoring: Stripe Radar. Stripe Radar is built-in fraud detection for all Stripe merchants; free for basic usage with optional Radar for Fraud Teams ($0.02 per charge for the advanced features). For an ecommerce store, Radar evaluates each transaction against fraud signals (card BIN, IP geolocation, customer behavior) and either allows, blocks, or 3DS-authenticates.
The 3DS (3-D Secure) toggle. Stripe Checkout’s payment intent UI can be set to always require 3DS (cardholder authenticates via their bank’s app).
For EU/UK buyers, 3DS is mandatory under PSD2; the issuer authenticates before the charge.
For US buyers, 3DS is optional; adding it adds 5-15 seconds to checkout but reduces chargeback risk materially (Stripe shifts the chargeback liability to the issuer for 3DS-authenticated charges).
Chargeback response: $15 per dispute, regardless of outcome. For each chargeback initiated, the merchant must respond with evidence within 7-21 days (depending on card network). The dispute submission process includes order receipts, shipping confirmation, customer communication logs, and proof of delivery. Stripe handles the upload through the dashboard.
International ecommerce: the +1.5% surcharges
Ecommerce businesses selling internationally pay +1.5% per non-US card on top of the base rate. For an ecommerce store with 15% international mix, the effective rate is about 0.225% higher than the published rate.
Stripe’s multi-currency support (135+ currencies) lets the store present prices in the buyer’s currency. The fee structure is the same; the conversion happens at settlement time. Conversion adds another 1% if you accept payment in a currency other than your settled currency. For most US ecommerce stores, settlement is in USD and the customer pays in their local currency with conversion fees applied.
Pricing summary for an ecommerce business
The decision matrix at common ecommerce volumes:
| Monthly volume | Stripe | Square Online | PayPal Commerce |
|---|---|---|---|
| $5,000 | ~$150 | ~$150 | ~$175 |
| $30,000 (15% intl) | ~$980 | ~$980 | ~$1,050 |
| $100,000 (intl+subscribe) | ~$3,200 | ~$3,200 | ~$3,400 |
The cost differences are minor; the operational difference matters more. Whichever processor your ecommerce platform integrates with cleanly (WooCommerce -> Stripe; Shopify -> Shopify Payments powered by Stripe; standalone -> any of three) is usually the right answer.
Pick by ecommerce platform
WooCommerce store: Install the Stripe Payment Gateway plugin (free); add PayPal Payments as secondary. Stripe Subscriptions if you need subscriptions.
Shopify store: Enable Shopify Payments in the admin. PayPal Payments as secondary. Shopify’s subscription billing or a third-party app if needed.
Standalone / niche ecommerce platforms: Stripe or PayPal typically have native integrations. Square Online is the right choice only if you also run Square POS in a physical location.
For the cost math at each card mix and volume tier, the payment processing fees page runs the full numbers.
For the practical 3-way comparison on API, hardware, and consumer trust, the stripe vs square vs paypal page covers the difference.
For the ecommerce platform decision (Shopify vs WooCommerce vs Square Online vs BigCommerce), the best ecommerce platform for small business comparison covers the stack selection.
For the subscription billing features at depth, the best subscription billing software for small business comparison covers the SaaS-billing toolset beyond the processor.
For the broader vendor comparison (Stripe, Square, PayPal, plus the high-volume interchange-plus options) at each volume tier, the best payment processor for small business comparison runs the full math.
Last updated: October 2026
