Refining payment gateway testing for secure transactions
  1. The Helcim Blog
  2. Merchant Guides

Refining payment gateway testing for secure transactions

Author Image

Robert Luong | January 31, 2025

“Payment gateways are critical steps in a user’s ecommerce journey. Ensure a secure and seamless experience through testing with help from this guide.”
8 min read
  • Content

    Every ecommerce journey is unique to the customer. From the way they find the product to the amount of research put into the decision and the final purchase itself, each stage represents a chance for customers to drop off and cost you a conversion.

    The most fraught stage is the checkout process for any ecommerce business. So many factors can affect the likelihood of a conversion and it is the role of your brand to instill as much confidence in potential buyers. Part of the puzzle in this process is your payment gateway itself, which manages the actual purchasing process itself and handles sensitive personal data, such as credit card and debit card information, along with other payment details.

    Payment gateways and their role in ecommerce

    Payment gateways are the backend that takes inputted customer information—personally identifiable data and payment information—and interfaces with the customer’s bank and the seller’s bank to approve the purchase and authorize a successful online transaction. It also needs to recognize and handle any failed transactions appropriately and relay the necessary error message and information to each party.

    In addition to this, a payment gateway needs to emphasize security at all stages of the transaction to ensure both parties are protected.

    The potential cyber threats at each step of the payment process open merchants and customers to fraud, data theft, and more. Online credit card transactions are particularly vulnerable because they involve the customer’s bank lending money upfront to complete the purchase. This makes the information transmitted by the payment gateway critical for the payment processor to verify the legitimacy of the transaction. As a result, the payment gateway reduces the likelihood of chargebacks and fraudulent activity.

    Types of payment gateways and their use case

    While all payment gateways will allow customers to make purchases, there are a few approaches that will be typically taken.

    Self-hosted payment gateways—the data collection of customer transactions is handled on-site and directed to payment processors to complete the transactions. The self-hosted payment gateway requires the merchant to handle data security and meet PCI DSS compliance standards.

    self-hosted payment gateways flow

    Third-party hosted payment gateways—websites direct customers to the payment processor directly during the transaction and are brought back to the site upon completion of the transaction. This payment gateway reduces the merchant's PCI burden, as sensitive data is handled by the gateway provider.

    Third-party hosted payment gateways flow

    API-based payment gateways—similar to a third-party gateway, the collection of data is handled by the payment processors themselves but is done while remaining on the merchant’s site throughout. This is achieved through API callouts embedded into the checkout process. Specific API definitions will change across third-party payment processors.

    API-based payment gateways flow

    Each approach will change the way your customers complete transactions with your business as well as the security dependencies that need to be put in place. Furthermore, the way you’ll test your payment gateway will be different; a payment gateway that remains on-site won’t need to test the hand-off process to a third party, for example.

    The benefits of testing in payment gateway management

    Testing your payment gateways is a necessary part of developing and maintaining your ecommerce business. Without consistent testing, it is all too easy for nefarious actors to identify vulnerabilities and exploit them, for customers to fall foul of bugs or unwanted website behavior, and leading to the ultimate loss of consumer confidence and bottom-line revenue.

    Effective testing will, above all, improve the user experience across your brand’s properties. This is critical, especially for smaller businesses lacking brand trust and recognition, as a sub-par checkout experience will cost more conversions than any other issue across a domain.

    Promotes a positive user experience

    Payment gateway testing will uncover roadblocks or challenges throughout the checkout process that could negatively impact the overall user experience. Given the tenuous nature of an ecommerce transaction—which becomes further fraught as the cost of goods increases—it is important to create the most seamless experience for your customers as possible.

    Furthermore, effective testing will ensure that any advanced features you have implemented on-site, such as call center integrations for customer support, personalization functionality, or dynamic cross-selling strategies, are working as intended and supporting a positive shopping experience.

    Ensures compliance & security

    All ecommerce domains are subject to a host of regulations and laws that safeguard individuals navigating the internet. The laws must be adhered to by any business operating in that given state.

    Ensuring you remain in compliance at all times will boost customer trust and ensure your ecommerce website is protected from any legal issues that may arise.

    Improves conversion rates

    Payment gateway testing is a proven method of improving your conversion rate at the checkout. It only takes the smallest wrinkle or perceived misleading payment processing trick for a customer to cancel the purchase and leave your website. Testing to ensure a robust experience will reduce points of friction and promote complete transaction journeys.

    Five types of payment gateway testing

    Types of payment gateway testing

    There are several different approaches to testing payment gateways. Each has its benefits and drawbacks, and you should consider which type of testing suits your business best.

    • Functional testing—testing the core functionality of the payment gateway and its ability to effectively handle a transaction from start to finish. Scenarios include successful payments, declined payments, refunds, partial payments, and edge cases like expired cards or incorrect CVVs.
    • Security testing—testing the vital security components in use throughout the payment process to ensure safe and secure use. It includes identifying vulnerabilities (e.g., SQL injection, XSS), ensuring PCI DSS compliance, and validating the effectiveness of encryption and tokenization methods.
    • User journey testing—testing to identify challenges or inefficiencies in the purchasing process that could be improved. Finding CSAT examples (customer satisfaction) to be analyzed further.
    • Integration testing—testing the various integrations and collaborations the payment gateway has with other third-party systems.
    • Performance testing—testing the real-world performance of the payment gateway itself when processing information and querying third-party sources. It ensures transactions are processed quickly and efficiently, even during busy periods like Black Friday.

    These form the majority of testing needs and will cover the needs of many businesses to ensure a high-quality and secure experience for their customers.

    Payment gateway checklist

    Before you begin setting up specific scenarios and situations to test your payment gateway with, it’s worthwhile sorting out some of the core essentials first. This checklist is a baseline point of reference that all payment gateways should pass to be considered acceptable. When writing your instructions for testing payment gateways, make sure you include this checklist. With this single point of reference for testers, you can ensure consistency in the way they make their initial assessment of your payment platforms.

    • Does the payment gateway support a transaction from start to finish?
    • Is the payment gateway functional across popular browsers, devices, and operating systems?
    • Do you offer popular proven methods of paying for products, such as Apple Pay, Gpay, PayPal, and finance?
    • Does your payment gateway use any integrations and do they interfere with the transaction process?
    • Are your customers given all the necessary information to complete the transaction?

    If you can answer yes to all of the above you’ll be ready to dig deeper and take on some of the more difficult and complex aspects of optimizing your payment gateway.

    Scenarios to test your payment gateways with

    You’ll want to test the various situations that a customer can find themselves in throughout the wider checkout process, as these will arise and any problems will lead to a lost conversion.

    While the following list is not exhaustive it should set you on the path to payment gateway optimization. Keep in mind that both manual testing and automated testing approaches will yield the best results when testing online payments.

    Personal Information Submission

    Personal information is a highly regulated area of online interaction. Businesses that collect and store personal information must do so securely and responsibly. Testing the information submission process—shipping and billing information, card information, and contact information—is the first step in all customer transaction journeys. Businesses can employ strategies seen in call center systems technology to safely gather and store personal information.

    Rejected payments & failed purchases

    Test the outcome of a customer’s failed attempt at a purchase across the entire transaction. Whether this is due to card information that is out of date, a failure to contact the relevant third party, a stock query failure, or a timeout from their network—all of these scenarios need to be explored and a viable solution found.

    Solutions can include messaging to support a second successful attempt or even communications via email in the event of a basket drop.

    Handling recurring payments & finance requests

    Any recurring payments such as subscription services that arrange standing orders or finance purchases that create a financial contract between merchant and customer need to be tested to ensure there are no loopholes or unwanted behaviors throughout the process.

    International orders

    International orders come with many added complications. Firstly, customers will need currency conversions done across the site and accurate to the current exchange rates. Secondly, your customers need to be provided with accurate shipping costs and information to make an informed decision, including the potential additions of import duties and taxes they may be subject to.

    Finally, you’ll need to ensure your payment process is compliant with any international territories you’re operating in, adding further testing scenarios to tackle.

    The next steps

    Payment gateway testing is an ongoing commitment that all ecommerce brands seeking to grow need to meet head-on. It is a challenging and lengthy process but will uncover truths about your domain that will have otherwise gone unknown.

    Done effectively, you’ll have an industry-leading checkout experience that boosts conversions, promotes a positive user experience, and builds loyalty and trust from your customers. The power of trust is stronger than almost any other part of your relationship with customers—you have to nurture it any way you can. Payment gateway testing is yet another key piece of that ongoing puzzle for you to solve.

    Add payment functionality to your website with Helcim

    If you want to add payments to your website quickly and easily—without the cost or hassle of hiring a developer—try Helcim’s Hosted Payment Page.

    In just a few clicks using our payment page wizard, you can select the information fields you want to collect, set the amount to charge, and customize the page’s design to match your brand perfectly.

    For businesses seeking a programmable solution, Helcim’s API offers the flexibility to integrate payments seamlessly. With over 80 different API actions, developers can build customized solutions tailored to your business needs.

    Add payment functionality to your website with Helcim

    Start accepting payments today.

    Create your free account instantly with no paperwork or commitments.

    Get started for free
    Call to action background image

    We're always
    here to help.

    New to accepting card payments? We take the time to help you understand how it all works so you can make the best decisions for your business.

    • Speak to a real person, fast
    • Experts you can trust
    Show more

    Have us contact you.

    Contact name cannot be blank
    Business name cannot be blank
    Please provide a valid email address
    Phone number cannot be blank

    The form was sent successfully!