E-commerce websites have several options when it comes to integrating payment gateways to accept customer payments. Each integration method has implications for PCI DSS compliance, including which Self-Assessment Questionnaire (SAQ) applies. Using iframes for payment forms can help reduce PCI scope in many scenarios. In this post, we'll cover the common payment gateway integration approaches, the applicable SAQs, and how iframes can simplify compliance—especially for the iframe approach.
Payment Gateway Integration Scenarios & Applicable SAQs
Scenario 1: Direct Post (SAQ A-EP)
- Customer enters payment details directly into a form on your site
- Upon form submission, data is posted to the payment gateway via HTTPS
- Your servers handle cardholder data but don't store it
- Since your system transmits card data, SAQ A-EP is required, which has 191 questions
Scenario 2: JavaScript (SAQ A-EP)
- Payment form is hosted on your site, but gateway-provided JavaScript collects card data
- Cardholder data is transmitted directly to gateway without touching your servers
- Your site never has access to full PAN
- SAQ A-EP still applies due to presence of payment form on your domain
Scenario 3: Redirect (SAQ A)
- Upon checkout, customers are redirected to gateway's hosted payment pages
- Cardholder data is entered on gateway's domain, not yours
- Qualifies for simplest SAQ A since payment info completely bypasses your systems
- Downside is customers leave your site, potentially impacting conversion rates
Scenario 4: iFrame (SAQ A)
- Checkout form is served within an iframe embedded in your site's page
- Customer enters payment details into iframe fields (e.g. hosted by Stripe, Braintree)
- Cardholder data goes directly to gateway without interacting with your servers
- Enables SAQ A eligibility while keeping customers on your domain throughout checkout
- Offers benefits of redirect method with a more seamless user experience
Why the iFrame Approach Stands Out
Using iframes for hosted payment fields provides substantial advantages:
Reduced PCI Scope & Easier Compliance:
- Cardholder data stays within the iframe, separate from your site
- This minimizes the systems subject to full PCI DSS controls
- Allows your site to be eligible for the simplest SAQ A, with only 22 questions
- Your payment iframe provider handles the intensive PCI requirements and liabilities
Seamless Checkout UX:
- Customers remain on your site's domain throughout the payment process
- Hosted iframes enable a responsive, mobile-friendly checkout experience
- Iframe content can inherit your site's look and feel for visual consistency
- Supports interactive features (input validation, error handling) for better usability
Faster Implementation:
- Embedding a pre-built iframe checkout form is quick and straightforward
- Requires minimal custom web development compared to direct integrations
- Uses standard, well-supported HTML functionality for reliability across browsers
The End Result with iFrames
By leveraging a PCI compliant payment gateway's iframe solution, e-commerce sites can achieve a highly secure and streamlined checkout workflow while keeping PCI scope to a minimum. Offloading the handling and transmission of sensitive cardholder data to your iframe provider greatly reduces the complexity of your own PCI compliance program. With a well-implemented iframe, you can deliver a user-friendly payment experience, instill trust, and boost sales conversions. Ultimately, iframes allow you to allocate more resources towards other security best practices while your payment partner expertly safeguards your customers' data.
Conclusion:
When evaluating payment gateway integration options, e-commerce merchants should carefully consider the PCI DSS implications and aim to minimize scope wherever possible. For most scenarios, using PCI compliant iframes for payment entry provides an optimal balance between simplifying compliance, maintaining the checkout UX, and supporting business growth. By keeping cardholder data isolated within iframe fields hosted by a trusted provider, your team can stay focused on delivering a great customer experience with confidence in your payment security.
