Which payment gateway is best for an eCommerce website?

Small business owners line up gateway pricing pages and compare the bold numbers — 2.9% + 30¢ here, 3.49% + 49¢ there — thinking the lowest sticker rate wins. It doesn't. Payment-industry analysts put it bluntly: "The headline rate is one line on a statement that often contains a dozen, and the lines that go uncompared are typically where the real money sits."

Hidden-fee benchmarks tell the real story. Monthly minimums can dominate costs for merchants under ~$10K/month in card sales. Per-authorization billing runs ~18% more expensive than per-capture pricing at an 85% authorization rate. PCI compliance fees add $10–$30/month per MID, with non-compliance penalties of $50–$200/month. Chargeback fees typically hit £15–£25 per dispute. Batch fees, decline fees, and early-termination clauses stack quietly. Gateway lock-in alone can cost ~£30,000 in dev time to unwind.

• Monthly minimums that punish low-volume months
• Per-authorization fees that bill on attempts, not successes
• PCI fees ($10–$30/month) plus non-compliance surcharges
• Chargeback fees (£15–£25 per dispute) regardless of outcome
• Early-termination clauses that lock you in for years

Pricing-model analysis confirms that tiered pricing is the worst model — explicitly "Best for: nobody. Avoid tiered pricing." Flat-rate looks simple but bundles cross-border and currency costs; interchange-plus wins at scale but demands volume transparency. The only way to compare is total effective cost at your actual transaction mix.

This is exactly why AI Business Sites routes payments through the client's own Stripe account via integrated Stripe Checkout — no platform markup, no hidden monthly fees, and the revenue relationship stays with the business owner. Stripe's domestic online rate of 2.9% + 30¢ ties for lowest on a $100 sale (netting $96.80), and its hosted checkout delivers +3.2% to +10.6% conversion over custom-built pages. The headline rate is a starting line — the finish line is what actually hits your bank statement.

Most small-business owners compare headline rates and call it a day. The real cost lives in the fees that don't show up on the pricing page — cross-border surcharges, currency conversion, monthly minimums, and chargeback penalties that can push an "affordable" gateway well past the competition.

On a $100 domestic online sale, Stripe nets $96.80 — tied with Square's paid tier and ahead of PayPal Checkout ($96.02) and Square's free tier ($96.40) — with no monthly or setup fees. That 2.9% + 30¢ flat rate holds for U.S. cards, but the math shifts fast once you sell internationally. Stripe's effective rate can climb to 5.4% + 30¢ on non-USD transactions before you add subscription or tax tooling, and cross-border fees typically add another 2–3% on top of base rates. Businesses processing over £50,000/month should negotiate custom pricing rather than stay on standard plans.

• Domestic online: Stripe 2.9% + 30¢ beats PayPal's 3.49% + 49¢ and Square's 3.3% + 30¢ free tier
• International non-USD: Stripe's effective rate can reach 5.4% + 30¢ plus 2–3% cross-border costs
• High volume: Custom pricing kicks in around £50,000/month
• Hidden fees: Chargebacks £15–£25, PCI fees $10–$30/month, per-authorization pricing bills ~18% more than per-captured at 85% auth rates

For AI Business Sites clients, the integrated Stripe Checkout routes money directly into the merchant's own Stripe account — the platform never touches funds. That preserves the ownership story and aligns with the market's shift toward hosted gateways, which now hold 52–57% of the market because they reduce compliance burden and deploy faster. Stripe's own data shows a 10.5% average revenue uplift from Payment Element migration and +3.2% to +10.6% conversion gains versus custom checkout pages. The bottom line: Stripe is the strongest default for domestic online-first small businesses, Square suits in-person merchants, and PayPal adds wallet trust at a premium.

Most founders obsess over basis points. The market data tells a different story: hosted gateways command 52–57% of the market because they offload PCI compliance and deploy in days, not quarters. Self-hosted alternatives demand $50,000–$150,000 per year in PCI DSS Level 1 certification alone — a burden no small business should carry.

Industry research shows SMEs drive 65% of gateway activity, precisely because hosted solutions remove the security burden. But the real leverage isn't compliance — it's conversion. Stripe's own matched-cohort study of 10,000 businesses found a 10.5% average revenue uplift after migrating to Payment Element. Wonderbly measured +3.2% conversion in the U.S. and +10.6% in Spain versus their custom-built checkout. BNPL adds another 9% lift, and Link one-click checkout delivers over 7% for returning customers.

• 10.5% revenue uplift from Payment Element migration
• +3.2% to +10.6% conversion vs. custom checkout pages
• 9% lift from BNPL aggregation
• 7%+ from one-click Link checkout

A conversion-optimized hosted checkout pays for its fee spread many times over. AI Business Sites bakes Stripe Checkout directly into each client's own Stripe account — money flows straight to the business, the platform never touches funds, and the conversion tooling ships day one. The basis-point debate misses the point: a 10% revenue lift on existing traffic is worth infinitely more than shaving 0.1% off the processing rate.

Most businesses evaluate payment gateways by headline rates — 2.9% here, 3.49% there — and miss where the real money leaks. The research shows that monthly minimums, authorization fees, PCI charges, and early-termination clauses often make a "cheaper" gateway cost more in practice, while gateway lock-in can demand ~£30,000 in dev time to escape.

Hosted checkouts dominate the market — 52–57% of revenue — because they remove PCI burden and deploy in days, not months. Stripe Checkout fits that model, but the AI Business Sites implementation adds a critical difference: payments flow directly into your own Stripe account. The platform never touches your funds. You keep the flat-rate pricing (1.5% + 20p UK / 2.9% + 30¢ US), the conversion-optimized checkout, and your revenue relationship — even if you leave.

• Stripe Checkout delivered a 10.5% average revenue uplift across 5,000 businesses via Payment Element migration
• Conversion gains of +3.2% in the U.S. and +10.6% in Spain versus custom-built checkout pages
• A 9% conversion lift from Stripe's BNPL aggregator — no separate integration required

This works the same way across every selling mode the platform supports: online stores, restaurant menus with pickup and delivery, bookable services with real-time slots, and ticketed events with waitlists. Gift cards, visit packages, and memberships all run through the same checkout into your Stripe account. The invoice side of the Jobs & Estimates module uses the identical flow — quotes approve online, invoices pay by card, and the money lands in your account. No platform intermediary. No gateway lock-in. Your Stripe account, your rates, your revenue relationship — portable from day one.

The fine print decides what you actually pay — not the headline rate. As one payments analysis puts it, the headline rate is one line on a statement that often contains a dozen, and the lines that go uncompared are where the real money sits.

Start by modeling your actual transaction mix before you compare a single rate card. Domestic vs. international matters enormously: Stripe's effective rate can climb from 2.9% + 30¢ to 5.4% + 30¢ on international non-USD transactions, and cross-border fees can add another 2–3% on top of base rates. One-time vs. subscription sales change the math too, since failed-payment recovery and recurring billing tooling vary widely between providers.

Then demand everything in writing. Before signing, request:

• A sample statement at your projected monthly volume — monthly minimums dominate costs for merchants under roughly $10K/month in card sales
• Contract redlines showing early-termination and auto-renewal language — gateway lock-in switching can cost around £30,000 in dev time
• Written confirmation of what's included vs. separately billed: PCI fees run $10–$30/month per MID, with non-compliance penalties of $50–$200/month
• A list of every fee that could appear over the contract's life — chargebacks typically run £15–£25 per dispute, plus batch fees and decline fees

A gateway that refuses to provide any of these in writing is the gateway with the most to hide.

On pricing models, keep it simple. Avoid tiered pricing entirely — industry guidance is blunt: it's best for nobody. Flat-rate pricing is the right default for most small eCommerce businesses because it's predictable and carries no monthly minimums, and it's what top providers like Stripe and PayPal structure their base plans around. Interchange-plus becomes cheaper at scale, but only once your volume justifies the accounting complexity — and custom pricing typically doesn't open up until around £50,000/month.

The last question is who owns the messy parts: fraud, disputes, retries, and refunds all end up on someone's desk, as payments founders note. Hosted checkout handles most of that for you — and it's why hosted gateways hold roughly 52–57% of the market.

If you want to see how this works in practice, book a free strategy call with AI Business Sites. We'll walk you through a done-for-you site with integrated Stripe Checkout running into your own account — money straight to you, no integration project, no obligation.