In the constantly evolving world of e-commerce, integrating a new payment method may seem like a simple technical update. However, behind this apparent simplicity lies complex challenges, both technically and business-wise. For e-retailers who want to optimize their conversion and adapt to the preferences of their customers, understanding these impacts is crucial.

1. Technical Impact: Much more than a simple button

Adding a new payment method is a delicate operation that touches deep layers of your system. The technical implications can be summarised in three key points:

Contextual Display and Eligibility Rules

It's not enough to just show a new logo on your checkout page. Each method has its own requirements, codes, and sometimes prohibitions. PayPal, for example, has strict rules about what types of products (such as alcohol, tobacco, or sexual content) its logo should not be used for. Integrating a new method therefore means:

• Understand and apply these eligibility rules : When, where and for what products can the method be proposed?
• Adapting the user interface (UI) and user experience (UX) : The display must be fluid, reassuring, and integrate harmoniously into the buying process, without creating confusion or error.
• Maintain compliance : Failure to comply with these rules may result in penalties or even the suspension of access to the payment method.

The “pipeline” of APIs: connecting to the payment ecosystem

Behind each payment method is a API (Application Programming Interface) A unique, specific language that your system needs to learn to “speak.” This is the true backbone of integration:

• One API per method : Each payment provider has its own documentation, its own technical specifications, its own security protocols. It's a constant process of translation.
• The crucial role of the integration team (plugin/connector) : This is where a team specialized in the integration of payment method APIs comes in. Their mission is to translate these heterogeneous APIs into a language that your platform can understand and use. They bridge the gap between the technical complexity of each payment method and the ease of integration on the merchant side.
• Constant updates : Partner APIs are constantly evolving, new error codes may appear... Successful integration requires regular monitoring and updates to remain compatible and benefit from the latest features or security patches.

The complexity of financial and accounting flows

The money is coming, but how? The addition of a new payment method introduces new financial cash flows, each with its own specificities in terms of:

• Different cash flow reports : Each payment partner may have a different report format (transaction log, refunds, fraud, chargebacks, etc.).
• Bank and Accounting Reconciliation : Unifying all these accounting journals is becoming a major challenge. This is to ensure that each transaction is correctly attributed, that the funds correspond to the actual receipts, to determine the amount of commissions per order, and that financial visibility is maintained.
• Management of disputes and unpaid invoices : Disputes, fraud, unpaid invoices must be managed properly, across all methods.

2. Business Impact: A Powerful Growth Driver

Despite technical challenges, integrating new payment methods is above all a strategic decision focused on growth and customer satisfaction. Concrete benefits have a direct impact on turnover.

Increase in the conversion rate

That is the main objective. By offering your customers' preferred payment methods, you reduce friction at the time of payment, which is the main factor in cart abandonment. A customer who can't find their preferred method is a lost customer.

Concrete example at Vertbaudet : Thanks to the integration of Purse, Vertbaudet noticed a Increase of 4 points in its acceptance rate for bank card transactions.

Access to New Markets and Adoption of Local Payments

For international expansion, it is essential. Each country has its own payment specificities. Integrating local payments opens doors to new customer bases.

Impact in the Netherlands : The Direct Transfer System iDEAL Represents More than 70% of e-commerce transactions In the Netherlands, making it unavoidable.

Read also: E-commerce in the Netherlands: trends, consumer habits and payment optimization

Impact in Switzerland : More than 5 million users Use TWINT, with 773 million transactions carried out in 2024. 50% of its transactions in Switzerland at Vertbaudet are carried out via TWINT.

Read also: E-commerce in Switzerland: trends, consumption habits and payment optimization

Impact in Belgium and Portugal : At Vertbaudet, 60% of transactions in Belgium Use Bancontact (against 10% previously) thanks to the addition of the QR code, and 54% of customers in Portugal Use MB Way.

Also read:

E-commerce in Portugal: trends, consumer habits and payment optimization

E-commerce in Belgium 2025: payment innovations to anticipate in order to remain competitive

Improving the customer experience

A smooth and familiar checkout experience builds trust and loyalty. The customer feels understood and secure.

Being among the first to offer an emerging payment method (such as BNPL or new mobile solutions) can position you as an innovative player and attract new customers.

BNPL example : The Buy Now, Pay Later (BNPL) market in Switzerland should reach 2.12 billion US dollars in 2025. The integration of solutions like Klarna and Riverty has facilitated access to split payments at Vertbaudet, contributing to the increase in the value of the average basket.

Future projections : Vertbaudet is even planning the adoption of 10% of the share of transactions with Apple Pay alone during its upcoming integration.

Cost optimization (long term) : Centralized and efficient payment management, even with multiple methods, can optimize transaction costs and simplify accounting reconciliation, reducing operational costs.

For a more in-depth study of the concrete benefits, download our complete customer case: Payment and expansion: Vertbaudet strengthens its international strategy. (add link)

3. Methodology and focus on the integration team: the key to success

The integration of a new payment method cannot be improvised. A methodology, supported by a dedicated team, is essential.

Choosing Well, Before Integrating

Before embarking headlong into the integration of a new payment method, a scoping step is necessary. It's not just about following a trend or giving in to a specific request: each method must meet a real need on the customer side, be consistent with your strategy, and compatible with your internal constraints.

The Central Role of the Plug-In Team :

1. API translators: This team is the backbone of integration. She specializes in reading, understanding and translating APIs that are unique to each payment method. Their expertise allows your platform to interface with any method without you having to manage the complexity of each specification. They build technical bridges.
2. Technological and regulatory watch: They are constantly on the lookout for changes in APIs, new payment methods, and regulatory changes (such as the GDPR or the PSD2), ensuring that all integrations remain efficient and compliant.
3. Maintenance and optimization: Their work does not end with initial integration. They ensure maintenance, bug correction, and continuous optimization of flows for maximum performance.

Consists Testing and Gradual Deployment

Each new integration goes through several test phases (technical, functional and performance).
Deployments are carried out on different environments, each of which has a specific level of requirements in order to arrive in production without risks.

Quotation expert team Q&A

Unification and reporting

The methodology should include tools to unify financial data from all payment methods, providing clear accounting journals and consolidated dashboards for a 360° view of your cash receipts.

RUN phase: maintaining performance over time

Once the integration has been completed and put into production, the work does not end there. To ensure optimal functioning and avoid regressions, the RUN phase is essential. It is part of a logic of continuous improvement.

Conclusion: Turning Complexity Into Opportunity with the Right Partner

The integration of new payment methods is a complex process, full of technical pitfalls and accounting challenges. However, it is a strategic investment that opens doors to better conversion, facilitated expansion, and increased customer satisfaction.

This is exactly where an expert partner like Purse makes all the difference. Our specialized integration team is your API “translator”, managing technical complexity so you can focus on your core business. We unify your financial flows and offer you the visibility you need to make the best decisions.

Stop letting the complexity of payments hold back your growth. Contact Purse to turn these challenges into real drivers of success!