Online Payment Integration: What You Need to Know Before Launching an E-Commerce Store

Launching an online store is not just about beautiful design and quality products. One of the critical elements of success is a properly configured online payment system. According to research, up to 70% of shoppers abandon their carts if the payment process seems complicated or unreliable. Let’s figure out what needs to be considered when integrating a payment system.

Choosing a Payment Gateway: Where to Start

A payment gateway is an intermediary between your store, the customer’s bank, and the acquiring bank. Your choice affects customer convenience, transaction security, and your costs.

Key Selection Criteria:

• Fees and rates. Most payment systems charge a percentage from each transaction (usually 2% to 5%) plus a fixed fee. Some also charge a monthly subscription fee. It’s important to calculate the total cost based on your average check and projected sales volume.
• Supported payment methods. The modern buyer expects variety: bank cards (Visa, Mastercard, MIR), e-wallets, Apple Pay, Google Pay, installments, and even cryptocurrency. The more options you offer, the higher your conversion rate.
• Geographical coverage. If you plan to sell abroad, make sure the gateway supports international payments and multi-currency transactions. Some systems operate only in specific regions.
• Settlement speed. Different systems transfer funds to your account with delays ranging from a few hours to several days. For startups with limited working capital, this is critical.
• Technical integration. Evaluate the connection complexity. There are ready-made plugins for popular CMSs (WordPress, Shopify, OpenCart), APIs for custom solutions, and hosted payment pages where the client is redirected to the payment system’s website.

Security: Mandatory Standards

Working with payment data carries serious responsibility. A data breach involving customers’ card details can not only destroy your reputation but also lead to fines.

PCI DSS Standard

Payment Card Industry Data Security Standard is a set of security requirements for all companies that process, store, or transmit cardholder data. PCI DSS certification is mandatory and includes:

• Use of secure networks and systems
• Encryption of cardholder data transmission
• Regular antivirus software updates
• Restricted access to data
• Regular system monitoring and testing

The good news: if you use a reliable payment gateway, most of the PCI DSS responsibility falls on them. It’s important to choose a provider with PCI DSS Level 1 certification (the highest level).

SSL Certificate

Your website must operate over HTTPS protocol. It encrypts data between the customer’s browser and your server. Modern browsers mark HTTP sites as unsafe, which discourages customers.

3D Secure

A technology for additional customer authentication (SMS code, biometrics, push notification in the banking app). It reduces the risk of fraudulent transactions and shifts the chargeback responsibility to the issuing bank.

Legal Aspects

Before accepting payments, it’s necessary to prepare a set of documents and comply with legal requirements.

Acquiring Bank Agreement

Acquiring means accepting card payments. You will need to:

• Open a business bank account
• Sign an acquiring agreement with a bank or payment aggregator
• Provide business registration documents

The process can take from several days to several weeks. Some industries are considered high-risk (gambling, financial services, pharmaceuticals), and obtaining acquiring for them is more difficult.

Return and Privacy Policy

Your website must include:

• Return and exchange policy
• Personal data processing policy (in accordance with GDPR and Federal Law 152-FZ)
• Public offer (sales agreement)

Payment Process UX

Even a perfectly configured technical setup won’t help if the customer finds it inconvenient to pay.

Checkout Process Optimization:

Minimum number of fields. Request only the necessary information. Use address autocomplete, city detection by IP, and saving data for repeat purchases.

Guest checkout. Don’t force users to register before purchasing. Offer to create an account after placing the order.

Transparency. Show all additional costs (shipping, taxes) upfront, not at the final step. This reduces cart abandonment rates.

Progress indicator. Show which stage of the payment process the customer is on (address → shipping → payment → confirmation).

Mobile optimization. Over 60% of purchases are made via smartphones. Make sure the payment form is responsive, buttons are large enough, and fields aren’t blocked by the keyboard.

Multiple payment attempts. If the card is declined, offer another or alternative payment method.

Technical Integration Details

Tokenization

Instead of storing actual card data, store tokens — encrypted identifiers. This simplifies PCI DSS compliance and enables one-click payments for returning customers.

Error Handling

Provide clear messages for different scenarios:

• Insufficient funds on the card
• Card blocked
• Limit exceeded
• Technical error

Don’t scare users with technical error codes — offer a solution instead.

Webhook Notifications

Set up automatic payment status handling. When a payment is confirmed, the system should:

• Change the order status
• Send confirmation to the customer
• Notify the warehouse for shipment
• Update data in the CRM

Test Mode

Before launch, make sure to test all scenarios in the payment system’s sandbox environment:

• Successful payment
• Declined transaction
• Partial refund
• Full refund
• Connection timeout

Common Mistakes

Limited payment methods. “We only accept cards” is a direct path to losing customers. This is especially true for younger audiences who actively use e-wallets.

Hidden fees. If the item costs 100 lei in the cart but the payment total is 150, the customer will feel deceived.

Lack of support. If a payment fails, the customer needs immediate help. An online chat or hotline is critical.

Ignoring mobile users. A non-optimized mobile payment form guarantees lost sales.

Underestimating testing. A failure at the payment moment is the worst-case scenario. Test on different devices, browsers, and internet speeds.

Conclusion

Online payment integration is a balance between customer convenience, security, costs, and technical capabilities. There’s no universal solution — the choice depends on your niche, business scale, target audience, and budget.

Start by analyzing your customers’ needs, exploring payment system offers on the market, calculating the economics, and allocating time for testing. Remember: payment issues mean not just a lost sale, but a lost customer who’s unlikely to return.

Investing in a quality payment system pays off through higher conversion, customer loyalty, and business scalability. Make this element a priority at the planning stage — and you’ll avoid many problems in the future.