Integrating International Payment Gateways into Shopify: Common Issues & How to Resolve Them

I. Common Issues in International Payment Gateway Integration on Shopify

1. Incorrect Configuration or Setup

A common issue is entering incorrect API keys or passwords or failing to activate the payment gateway according to the proper setup procedure. For instance, merchants using Stripe may encounter failed transactions if they mistakenly use an API key in test mode instead of live mode, preventing customers from completing their payments.

Solutions:

• Access Shopify Admin > Settings > Payments to verify and authenticate credentials.

• Use test mode to trial transactions before going live.

• Ensure the gateway is in Live Mode (not Test/Sandbox) before accepting real payments.

• Confirm that the payment method has been fully activated in Shopify after setup.

• Contact the gateway’s support team to confirm the correct setup. 

2. Currency Conversion and Multi-Currency Limitations

Some international payment gateways impose high conversion fees (typically 3–5%)and do not fully support local currencies. If the gateway does not support the customer’s currency (e.g., KRW, AUD, CAD, or EUR), the system will automatically convert the payment into another currency (such as USD or EUR). In this case, both the customer and the merchant incur conversion fees, increasing costs and creating a poor payment experience. 

Moreover, exchange rate fluctuations and foreign transaction fees may also significantly reduce revenue if not properly managed. For example, Japanese customers who see a noticeable difference between the listed price and the amount charged, caused by currency instability or foreign exchange fees, may doubt the transparency of pricing and become less likely to complete their purchase.

Solutions:

• Define your policy: display prices based on customer location or allow currency selection.

• Use gateways/apps that support multi-currency functionality.

• Test checkout on multiple devices and browsers.

• Ensure mobile-friendly checkout compliance.

3. Non-Compliance with Local Regulations

Major markets such as the EU, the UK, and the US each impose distinct regulatory requirements, which often create challenges for sellers and increase the risk of non-compliance. For example, in the EU, the PSD2 directive mandates Strong Customer Authentication (SCA), with non-compliance potentially resulting in penalties of up to EUR 5 million or 3% of global annual revenue. Similarly, misreporting or incorrectly collecting VAT within the EU can cause losses in the hundreds of millions of euros annually.

In addition, some international payment gateways conduct periodic audits and may require re-verification of KYC/KYB documents. If not completed, merchants may have their funds temporarily held or face restrictions on transactions.

Note: 

KYC (Know Your Customer): The process of verifying a customer’s identity and address to ensure compliance and prevent fraud or money laundering.

KYB (Know Your Business): The process of verifying a business’s legal status, registration, and bank accounts to ensure legitimacy and regulatory compliance.

Solutions:

• Use automated tax tools like TaxJar or Avalara for real-time calculations.

• Conduct periodic compliance audits and consult with legal experts.

• Choose PCI DSS-compliant gateways that meet local regulatory standards..

4. Technical and Connectivity Issues

Payments may fail due to Shopify server outages, user-side network issues, or disruptions within the international payment gateway’s infrastructure. For instance, during high-traffic events such as Black Friday or Cyber Monday, some stores have reported a sharp increase in payment failure rates caused by server overload.

Solutions:

• Monitor status.shopify.com for system updates.

• Clear browser cache/cookies or try different browsers/networks.

• Set up a backup gateway (e.g., using both Stripe and PayPal) to avoid revenue loss.

5. Payment Methods Not Displaying or Being Declined

Causes may be conducted from both the customer and the payment provider, such as entering incorrect card details, insufficient funds, a blocked card, or transactions being declined under the bank’s or payment provider’s fraud prevention policies. For example, certain international gateways such as Stripe or PayPal may reject a transaction if the IP address is associated with a restricted country or if the payment activity appears suspicious.

Solutions:

• Communicate the reason for the transaction failure to the customer.

• Advise them to verify their card, balance, or choose an alternative payment method.

• Contact the payment provider for investigation if the issue persists.

II. Frequently Asked Questions (FAQ)

In addition to questions about the process of resolving international payment gateway integration issues on Shopify, merchants often raise concerns about specific details, such as supported countries for each gateway and how to handle unexpected situations.

1. Does Shopify support all international payment gateways?

No. Shopify only supports gateways from its integration list or those connected via API. Check compatibility before selecting a provider.

2. How can I determine whether a transaction failure is due to technical issues or customer error?

Review the error code and decline reason in the gateway’s dashboard. Technical errors often relate to connectivity, while customer errors involve incorrect details or verification issues.

3. How long does it take to resolve payment errors?

This depends on the issue type. Simple errors (e.g., test mode left on) can be fixed within hours, while complex technical issues may require 2–3 days.

4. What should I do if payment methods are not displaying?

Check anti-fraud filters and test on different devices/browsers to rule out display issues.

III. Why It Is Essential to Address International Payment Gateway Integration Errors on Shopify

Effectively resolving payment-related issues not only protects your business but also enhances brand credibility on Shopify. Key benefits of promptly addressing integration errors include:

1. Safeguarding Revenue

International payment issues can result in losses of up to 0.47% of total annual revenue due to failed transactions or chargebacks. Timely resolution ensures stable cash flow and uninterrupted financial planning.

2. Optimizing Customer Experience

Research from the Baymard Institute shows that 10% of customers abandon their carts when their preferred payment method is unavailable. Addressing display errors or limited payment options helps customers complete payments more easily and enhances the overall shopping experience.

3. Enhancing Analytics and Strategy

After fixing integration issues, data from the Shopify dashboard provides detailed insights into customer behavior, including preferred payment methods, cart abandonment rates, and the timing of completed transactions. Analyzing this data helps you optimize the checkout experience and adjust business strategies, thereby improving sales performance and revenue growth.

4. Increase Conversion Rate

Fixing display or availability issues can boost conversion rates by up to 7.4%.  Providing a seamless checkout experience also boosts the likelihood of customers completing purchases and returning for future orders, ultimately maximizing store revenue..

IV. Conclusion

Integrating international payment gateways into Shopify is vital for driving revenue, improving customer experience, and expanding into global markets. Proactively resolving common issues ensures smooth, secure transactions and maximizes business performance.

Most problems can be resolved quickly with a clear understanding of their causes, though some require specialized expertise and longer resolution times. For tailored support with international payment gateway integration or troubleshooting on Shopify, contact Sliner for professional guidance and optimized implementation from the start.