Errors in payment gateway functionality have enormous potential to derail the relationship between consumer and vendor. Customers expect seamless, functional transactions without confusing messages or complicated steps. They expect security, privacy, and safeguards against over or underpayment. Any misstep in the payment process can lead to abandoned shopping carts, deleted apps, and consumer frustration.

The best way to ensure payment functionality is with a clear payment gateway testing strategy. These five best practices help common issues be identified and rectified before causing severe problems in merchant systems.

Five best practices for payments testing

Payments testing is guided by a set of best practices that inform how the tests are designed, executed, and reported on to deliver dependable, robust testing.

1. Combine automated and manual testing

Software testing best practices across most industries point to the efficacy of fusing manual and automated testing. Start by determining which test cases are best suited for automation and which need a human touch.  

Automated testing can help create variables, like location identifiers, postage calculations, and currency conversion rates to test use cases.

Performing a functional test of a “pay now” button, or a performance test to see how the server can handle multiple payments processing at once, is perfect for automation as you can quickly execute tests at your current scale.

Beyond functionality, payment gateways must offer a great user experience. This, of course, is best tested by real people on real devices. Usability testing focuses on the experience of using the payment gateway to ensure it is easy to navigate.
Using real devices to test location, O/S and device compatibility, and network realities allow the opportunity to match the diversity of actual users.

2. Execute multiple integration test cases

Not only does the source code need to be bug-free, but connections between a merchant, financial institution, vendor, and device need to be seamless every time.

It’s crucial to run an integration test with the addition of each new integration offering. Adding Apple Pay, contactless pay, Klarna, Chime? Execute a new integration test. All new payment options will need to be independently tested and confirmed before accepting that payment method from a customer.

If your e-commerce website adds a new shipping option, country, or currency – it needs to add another test to ensure functionality.  

When a top-15 U.S. iOS e-commerce company partnered with Testlio to deploy a testing team (from 10 countries + across four continents) to conduct localized payments testing, they uncovered a huge bug.

Testers discovered a value misinterpretation of their country’s penniless currency at checkout. A bug caused purchases without an even amount to round up, in some cases increasing the cost of an item (e.g., $1.05 became $2). 

The client used this information to develop a localized payment system and pricing model to prevent price round-ups.

Executing multiple location test cases can use region-based devices to verify that the payment gateway can handle customer locations and calculate the proper specifications (sales taxes, global shipping fees, conversion rates, import tax).

3. Use a scalable testing platform

Utilizing a scalable testing platform can significantly expand the testing functionality and test cases as your business grows. 

Platforms, a mix of software, testers, and service, should offer flexibility, like testers leaping into action quickly to work in short bursts to augment your QA team during periods of peak demand. Testers then intentionally go dormant until the next run. As a result, capacity is available only when needed, and you don’t pay for idle personnel.

Testing for payment gateway performance will require developing scenarios and then running through each one to verify the payment gateway processes transactions correctly. Some test cycles may be larger than others (think performance testing for the maximum number of simultaneous transactions), and using a scalable platform will cater to specific run needs. 

Having a platform that can adjust testing teams as needed helps you scale. Though you may begin with a few countries, five major financial institutions, and three currencies accepted on your e-commerce platform, you need a flexible platform to support extended testing if you want to widen your user base.

4. Run a pre-test pilot

Running a pre-test pilot is a handy safeguard before all of the data is loaded and scheduled to run. 

Starting with a small run doesn’t risk significant delays or reruns if anything needs to be adjusted or added before the full run. Adopting a pilot test approach allows the test parameters and design to be assessed (and even re-designed if necessary).

For example, if there’s a significant source code issue in encryption, starting with a pilot run to eliminate and rectify will allow the second full-production run to find more minor bugs.

Running a pre-test pilot will establish suitable time frames needed for test team coordination. Your team should also manage task reports transparently while accumulating data to be filed in a final report.

5. Prioritize user experience

During testing, consider the customer’s POV and prioritize communication and clear UX. 

If payment is successful, confirm a payment confirmation is provided to the customer to avoid cloned orders. Likewise, a payment failed notification must be available if a payment fails, preferably with helpful information to rectify. 

Customers frequently abandon their cart because of technical bugs – but also if the process feels overcomplicated, requires too much information, or in-app popups.

Test for common triggers that can emotionally impact the end-user: time outs, discount code application, button fails, and currency conversion issues. 

Why test for payments?

Payment gateway testing will ensure customers, merchants, and financial institutions operate through a platform with the highest functionality and usability parameters.

In the best cases, testing payment gateways taps into a global network of testers that can deploy industry expertise and burstable testing as new features are explored. Skilled testers take on the role of both customers and merchants to perform a suite of tests that utilize powerful test management software to perfect the user experience from functionality to usability.