Certified payment integrations: process, requirements, and best practices

Not all payment integrations are created equal. With major payment processors and acquirers, writing to an API is only half the job. The other half is formal certification — a structured approval process where your integration is verified before going live.

We’ll walk you through why payment integration certification exists, what happens behind the scenes, and why it matters for secure and reliable transaction processing.

What is payment integration certification?

It goes beyond basic sandbox testing. Providers issue structured test scripts and won’t release live credentials until every required scenario passes. Expect to test success and failure flows, logging, data handling, and edge cases — often across multiple rounds.

Think of certification as your integration’s final exam — a deep check to ensure everything works exactly as it should before real money is involved. It provides assurance to both the provider and the merchant that every stage of the payment flow – from data capture to confirmations and callbacks – performs reliably under real-world conditions.

Dmytro Soboliev

Integration Manager at Corefy

Why certified payment integrations matter

Not all providers require certification, but many do — especially in regulated markets or with complex flows. Certification serves several critical purposes that protect both the provider and the merchant.

Ensuring transaction accuracy

Payment processing involves numerous interconnected systems, and even small formatting errors can result in lost payments, duplicate charges, or settlement issues.

Certification compels the integrator to demonstrate that every request and response is handled precisely as specified. This helps providers catch potential issues before they affect live customers, reducing the risk of costly financial errors.

Strengthening security and compliance

Because payment data is highly sensitive, providers must ensure that integrations don’t introduce vulnerabilities or violate security standards.

Payment integration certification typically includes checks to confirm that:

• Cardholder data is stored securely
• Tokenisation or hosted fields are used where required
• Integration flows comply with PCI DSS and data protection requirements

Preventing fraud and operational errors

Incomplete or inaccurate integrations can easily lead to fraud risks or frustrated customers. If a system fails to transmit key fields such as CVV, AVS (billing address), or mishandles error responses, it may treat declined transactions as successful or vice versa.

The payment provider certification process includes testing a wide range of scenarios, including invalid card numbers, insufficient funds, and expired cards, to verify that the merchant interprets responses correctly and handles callbacks reliably.

By catching issues early, providers significantly reduce chargebacks, disputes, and post-launch incidents.

Brand protection

A faulty integration can damage reputations on both sides. Duplicate charges, system outages, or failed transactions can quickly erode trust and draw regulatory attention.

By certifying integrations, providers maintain a consistent level of reliability across their ecosystem. Many even publish lists of certified solutions — software or hardware tested and approved for use on their platforms — which they can recommend to partners and merchants.

What does the payment certification process involve

While each provider’s process differs, the payment certification checklist typically includes:

Planning & scope definition

Start by agreeing with the provider on what needs to be certified. This includes:

• The transaction types you’ll support (e.g. authorisation, capture, refund, void, recurring)
• The payment methods you’ll enable
• Any special features (e.g. 3DS, tokenisation)

The provider will typically give you a certification guide or test plan outlining every scenario you must pass.

Prepare and test in the sandbox

Use the provider’s sandbox environment to build and debug your integration. You’ll get test credentials, special card numbers, and values designed to simulate real-world scenarios — including edge cases like insufficient funds or expired cards.

This is your chance to catch issues early and make sure your system behaves exactly as expected.

Run formal test cases

Next comes the official test execution, often supervised by the provider’s certification team. You’ll need to:

• Execute each test case precisely
• Match every expected result — including success flows, declines, and errors
• Provide logs, screenshots, or API responses to prove correct behaviour

Certification is exacting — even small deviations can trigger a re-test.

Fix and re-test if needed

It’s common for a few tests to fail the first time. You’ll need to troubleshoot, correct the issue, and rerun the affected cases. Preparation helps reduce iterations, but debugging and refinement are part of the process.

Get certified and go live

Once all mandatory tests pass, the provider will formally approve your integration. You’ll receive production API credentials or a switch from sandbox to live mode. At this point, you’re authorised to process real payments.

Record and document your results

Throughout the process, you’ll maintain records of the tests. Most providers require you to fill out a test results log, recording the date, test case, and outcome (pass/fail, with any notes). This becomes an artefact proving compliance.

Monitor post-launch performance

While not officially part of certification, providers often observe the first weeks of live traffic to confirm production behaviour matches the certified one.

Each provider gives the certification journey its own twist. Some run the process through dedicated online portals, automating test execution and final approvals to cut down time and manual work. Others handle the process manually. Yet, at its core, every certification follows the same rhythm — plan, test, approve, maintain.

Dmytro Soboliev

Integration Manager at Corefy

Audits and recertification: keeping integrations up to date

Certification isn’t a one-time milestone. Providers may conduct periodic audits of certified integrations, especially for large partners or high-risk use cases.

Recertification is more common than full audits and is typically triggered by change. The following situations often require it:

• API upgrades. When your provider releases a new version, it may include altered message formats, updated field requirements, or validation logic changes. Recertification confirms that your integration remains compatible and production-ready.
• Adding new transaction types or payment methods. Expanding functionality, such as adding Apple Pay, ACH, or 3D Secure 2.0, usually triggers a focused recertification.
• Significant code or platform changes. If you refactor backend logic, switch e-commerce platforms, or update how callbacks and responses are handled, you’ll likely be asked to revalidate the integration. This helps catch any regressions or unintended issues before they affect live traffic.
• Lapse in activity or compliance. If your integration has been inactive for a while — or if your PCI DSS certification lapses — your provider may suspend live access until you complete the necessary checks.
• Scheme mandates or regulatory updates. When card networks introduce new technical or security requirements — such as 8-digit BINs, new response codes, or the migration from 3DS 1.0 to 3DS 2.0 — providers push updates downstream.

Recertification follows the same fundamental stages as the initial process — plan the scope, execute the required test cases, and obtain formal approval. The difference is in scope and speed: retests usually cover only the changed or newly added components, allowing for faster completion.

Dmytro Soboliev

Integration Manager at Corefy

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Integration certification case from our practice

An iGaming company needed to certify their payment integration with Worldpay, one of the world’s largest acquirers. This step was essential to unlock new markets.

By the time they joined Corefy, they’d already spent over nine months navigating the certification process independently. As they put it, “that’s enough time to carry a baby to term — and we couldn't even get a terminal turned on.”

Worldpay certification process is rigorous — and without hands-on experience, it can be difficult to keep momentum. Certification success often comes down to how well the provider, client, and integrator align.

We worked closely with both the client and Worldpay to reframe the process. Our team helped coordinate timelines, interpret requirements, and troubleshoot edge cases as they came up. The client stayed actively involved, and Worldpay’s team was responsive and clear.

Olena Domaieva

Lead Onboarding Manager at Corefy

With aligned efforts and open communication on all sides, we completed the certification two weeks ahead of schedule. What usually used to take months became a structured, efficient rollout — helping the client go live and scale sooner than expected.

Final thoughts

Certification is challenging but essential. It guarantees compliance, stability, and trust in every payment flow. Through continuous collaboration with leading acquirers and gateways, we’ve already completed certification with major global providers, including Visa, Worldpay, Paysafe, Shift4, and PayNearMe.

Corefy’s certified integrations are launch-ready for clients. There’s no need to navigate the certification process yourself — simply connect your merchant account credentials, and you’re ready to transact.

We’ve taken care of the heavy lifting: fulfilling each provider’s technical, security, and compliance requirements so you can enter new markets and start processing with confidence.