Below is a concise, practical guide to secure payment-gateway options for e‑commerce, what security features to require, and how to choose/implement the right one for your store.

Top payment-gateway options (strengths at a glance)

• Stripe — Developer-friendly, broad global payment method coverage, built‑in fraud tools and tokenization; strong choice for custom checkouts, subscriptions, marketplaces and scale. (Stripe.com)
• PayPal / Braintree — Easy brand recognition + wallet support (PayPal, Venmo), good for merchants who want fast onboarding and PayPal buyers; Braintree offers advanced SDKs, hosted components, and vaulted cards. (PayPal.com)
• Adyen — Enterprise/global-first platform with unified gateway, advanced risk tools, and wide currency/country support; common for large merchants with high cross‑border volume. (reuters.com)
• Checkout.com — Focus on global coverage, transparent pricing models, strong data/analytics and ML fraud protection; good for mid-to-large merchants needing international reach. (Checkout.com)
• Square — Very easy setup, all‑in‑one for small/brick‑and‑click merchants, predictable flat rates and integrated POS/online ecosystem. Good for small stores and omni‑channel sellers. (squareup.com)
• Authorize.Net — Longstanding gateway, good if you already use an acquiring bank or want a gateway-only option; includes fraud rules, tokenization and recurring-billing tools. Often used by SMBs that prefer a gateway + separate merchant account. (technologyadvice.com)

Key security features to require (must-haves)

• PCI DSS compliance + scope reduction: provider should support hosted elements or tokenization to minimize your PCI scope (SAQ‑A/SaQ‑A‑EP options). Confirm Level 1 / current PCI status in provider docs. (Stripe.com)
• Tokenization / vaulting: never store raw card numbers on your servers — use tokens to store/reuse payment methods. (Stripe.com)
• 3‑D Secure / SCA support: required for many European transactions and useful to shift fraud liability for certain flows — ensure the gateway supports 3DS2 and friction-reducing fallbacks. (Stripe.com)
• Fraud detection / risk tools: machine learning scoring, rules engines, velocity checks, IP/geolocation, and chargeback management. Enterprise gateways provide advanced ML and customizable rules. (Checkout.com)
• TLS + modern encryption, secure webhooks with signature verification, and strong auth for dashboard/API access (mTLS/2FA). (Stripe.com)
• PCI reporting, audit logs, SOC2/ISO certifications (for higher assurance) — check provider compliance pages.

How gateway architecture affects security and compliance

• Hosted checkout (redirect or embeddable hosted widget): least PCI scope for you; provider handles card capture and storage. Good for faster compliance and lower risk. (PayPal.com)
• Client-side tokenization + API calls: card data is sent to provider via client SDK, you receive a token — moderate complexity, low PCI scope. (Stripe.com)
• Full server-side card handling: highest control but highest PCI burden (avoid unless necessary).

Which gateway is best for different situations

• Small e‑commerce, simple checkout, local sales, POS tie‑in: Square (easy, predictable fees, integrated tools). (squareup.com)
• Online store wanting maximum customization, subscriptions, marketplace payouts, or global expansion: Stripe (rich APIs, billing, Connect, Radar fraud prevention). (Stripe.com)
• Want PayPal/Venmo buyer base and wallet options: PayPal/Braintree (brand recognition, hosted experience for PayPal). (PayPal.com)
• Large/global/enterprise with high cross‑border volume & complex routing: Adyen or Checkout.com (global acquiring relationships, advanced fraud/risk tooling). (reuters.com)
• Already have an acquiring bank or want gateway-only: Authorize.Net (gateway-only plan, good integrations and fraud rules). (technologyadvice.com)

Costs & pricing model notes (what to compare)

• Interchange‑plus vs flat rate vs blended: interchange‑plus often lowest for high volume; flat/blended easier to predict for small merchants. Ask for sample monthly cost estimates. (Checkout.com)
• Monthly gateway fees, per‑transaction fees, chargeback fees, cross‑border/foreign currency surcharges, and added costs for advanced fraud tools or recurring/billing features — get a written pricing example for your expected volume. (PayPal.com)

Practical implementation checklist (quick, secure rollout)

1. Choose 2–3 gateways that match business size, geography, and payment methods.
2. Create test/sandbox accounts, run end‑to‑end checkout flows, test 3DS flows and declines. (Stripe.com)
3. Use client SDKs or hosted components to tokenize card data (avoid storing PANs). (Stripe.com)
4. Enable fraud tools and tune rules with small live‑volume testing window. (Checkout.com)
5. Configure secure webhook handling (validate signatures) and restrict API keys with least privilege + rotate keys regularly. (Stripe.com)
6. Verify PCI DSS compliance requirements for your implementation and fill the correct SAQ; keep evidence of vendor compliance. (support.Authorize.Net)
7. Monitor chargebacks and disputes; implement a documented dispute response workflow. (PayPal.com)

Recommended next steps (fast)

• If you want minimal effort and fast onboarding: start with Square or PayPal (hosted flows). (squareup.com)
• If you expect growth, subscriptions, marketplaces, or global expansion: evaluate Stripe and Adyen in sandbox; request custom pricing and ask about local acquiring in your target countries. (Stripe.com)
• Get price quotes from gateways with your real projected volumes and ask for written details on international fees, refund/chargeback costs, and fraud tool pricing. (Checkout.com)

If you’d like, I can:

• Compare 2–3 gateways side‑by‑side for your store (fees, countries, payment methods, dev effort) — tell me expected monthly volume, average order value, and primary countries; or
• Provide a short PCI scope checklist and recommended SAQ for a hosted/tokenized checkout.

Which of those would be most helpful next?