Marketplace guide: how BaaS and PSPs optimise your payments

Marketplaces are multiplying and now represent a growing share of e-commerce. Behind the apparent simplicity of making a purchase on a marketplace lies a complex payment processing infrastructure, where two players perform essential and complementary roles: the Payment Service Provider (PSP) manages the collection of incoming transactions, while Banking-as-a-Service (BaaS) solutions orchestrate outgoing payments to sub-merchants and the management of commissions.
With this special marketplace guide, discover how this complementarity helps optimise the customer experience while simplifying administrative and financial management.

A PSP, or Payment Service Provider, is a company that provides a technical solution enabling e-merchants and marketplaces to accept online payments securely.

The payment services market is strictly regulated in France and across Europe. Three types of players can provide these services:

• traditional banks,
• payment institutions,
• electronic money institutions.

To offer payment services, they must:

• obtain authorisation from the Autorité de contrôle prudentiel et de résolution (ACPR),
• comply with regulations, in particular the European PSD2 (Payment Services Directive), which came into force in January 2018.

For marketplaces, the PSP is the gateway for financial flows. It captures payments from end customers via card payments, e-wallets or bank transfers, before these funds are redistributed to the platform’s various sellers.

The PSP orchestrates the payment process. As such, it plays a key role at every stage to ensure transaction security and speed.

When a customer makes a purchase on a marketplace, they enter their payment details via a secure web page provided by the PSP. The PSP’s system immediately encrypts this sensitive data to ensure secure transmission. This protection of the payer’s and seller’s financial data relies on an infrastructure compliant with PCI-DSS certification, which is essential for acquiring payment flows.

At the time of a payment transaction, the PSP requests authorisation from the customer’s issuing bank to check fund availability. It also verifies the payer’s identity through strong customer authentication. This step is crucial in limiting the risks of fraud and unauthorised transactions.

Once the transaction is authorised, the PSP coordinates the transfer of funds between the customer’s bank account and the merchant’s account.
This acquisition process generally takes place at the end of the day:

• The merchant sends a batch of authorised transactions to the PSP.
• The PSP forwards them to the acquiring bank.
• The acquiring bank transfers the funds to a safeguarding account held by the PSP, which then forwards them to the merchant’s bank.

Beyond transaction processing, Payment Service Providers offer a comprehensive ecosystem of features.

The PSP provides access to multiple online payment methods: payment cards (CB, Visa, Mastercard), online wallets, direct debits and financing options such as instalment payments (BNPL). This diversity is a key conversion driver for marketplaces.

Security measures include the detection of suspicious activity using advanced algorithms, tokenisation of sensitive data, and additional controls that can be configured according to the company’s activity. These measures significantly reduce exposure to threats and protect both customers and merchants.

The PSP provides a comprehensive back-office to manage transactions. With the insights available, businesses can analyse sales, identify trends and optimise the financial management of their marketplace.

International marketplaces can rely on PSPs to manage multiple currencies and facilitate local payments. This functionality supports expansion into new markets while delivering an optimal customer experience.

Acquiring PSPs support businesses in handling payment disputes and chargebacks, a process that can be complex and time-consuming without dedicated expertise.

Payment Service Providers therefore offer many options to secure and facilitate the acceptance of incoming payments. However, to also manage outgoing payments—such as payouts to sub-merchants or commission distribution—integration with a Banking-as-a-Service platform is essential.

Between volumes (number of customers, merchants, transactions, accounts and banks), regulatory obligations and specific mechanisms such as payment collection on behalf of third parties, a marketplace’s payment architecture can quickly become complex. Combining a PSP with a BaaS solution represents a major advantage, offering strategic complementarity on several levels.

By using a PSP and a BaaS platform authorised by the ACPR, a business reduces the regulatory burden and shortens the time required to launch its online marketplace. In particular, it avoids the requirements associated with obtaining a payment institution licence, including:

• sufficient initial capital,
• a governance framework,
• an internal control system,
• an AML/CFT framework,
• effective risk detection and management procedures,
• professional civil liability insurance.

The review process takes between 6 and 12 months for a complete application, with possible extensions if additional information is required.

The PSP secures and processes payments made by buyers, while the BaaS solution orchestrates the distribution of funds to the platform’s various sellers and automatically deducts the marketplace’s commission. This automation eliminates the manual handling of hundreds or thousands of transfers, reducing errors and processing time.

A purchasing journey that is too long, feels insecure or lacks payment options may lead customers to abandon their online baskets—at best a lost sale, and at worst the loss of all future transactions with that customer. Choosing a high-quality PSP combined with a BaaS solution helps reduce friction and significantly improve conversion rates.

Registered PSPs and BaaS solutions must comply with the strictest standards in terms of data security and anti-money laundering. Implementing these regulatory requirements helps protect merchants and customers, thereby strengthening trust.

As a marketplace grows, transaction volumes increase. The technical infrastructure provided by a PSP and a BaaS solution scales with the business, without requiring major investment in development or infrastructure.

Selecting a PSP is a strategic decision that directly impacts a marketplace’s operations and growth. Several criteria should guide the choice.

Carefully review the proposed fees: setup fees, transaction fees (percentage and/or flat fee), monthly fees, dispute fees and currency conversion fees. Traditional banks generally offer lower acquiring fees through Secure Remote Sales (VADS) contracts. Payment institutions may charge slightly higher rates but often provide more features.

Ensure that the PSP is compatible with your e-commerce platform and can easily integrate with your BaaS solution. Most providers offer APIs to simplify technical integration, but pay close attention to support: clear documentation and responsive technical assistance are essential to minimise implementation time.

Check that the PSP supports the payment methods preferred by your customers (physical payment cards, virtual cards, e-wallets, bank transfers).
If your marketplace operates in B2B, direct debit and bank transfers can be a relevant alternative to cards, which are often too limited for intercompany transactions, as they allow for large amounts and payment schedules.
If you operate internationally, the availability of specific local payment methods can significantly improve your conversion rate.

Plan payout timelines that take into account the safeguarding of funds. This mechanism, which separates funds held by a payment or electronic money institution, fulfils a legal obligation designed to protect third-party funds.
This delay can be up to five days for an electronic money institution.

Choose a provider offering responsive customer support, ideally available 24/7 through multiple channels: phone, email and live chat. The quality of technical support is particularly critical during the integration phase and in the event of an incident.

An intuitive management interface with advanced reporting capabilities makes it easier to monitor activity, identify trends and detect potential anomalies. This data is invaluable for optimising your commercial strategy.

Trust is a decisive factor in online commerce. A well-established PSP—whether a traditional bank or a recognised fintech player—reassures customers and can help reduce cart abandonment.

During the launch phase or when operating in a limited geographical market, a marketplace generally benefits from remaining with a single PSP. One interface, one point of contact, one integration: working with a single provider simplifies administrative and technical management.

However, a multi-PSP strategy becomes relevant at higher volumes of activity. Several situations can justify the added complexity of this approach.

Geographical diversification: Depending on the location of sellers and buyers, working with several providers across different regions helps optimise conversion rates by offering the most relevant local payment methods.

Resilience and business continuity: Switching acquisition from one PSP to another helps avoid disruptions in the payment chain. Moreover, each PSP is subject to regulatory requirements to ensure business continuity and disaster recovery.

Cost optimisation: Depending on transaction type and geographical origin, fees can vary significantly between PSPs. A multi-PSP strategy allows transactions to be intelligently routed to the most cost-effective provider.

Pricing negotiation: Working with multiple PSPs strengthens your negotiating power and can help secure better pricing conditions.

For marketplaces, combining a high-performance Banking-as-a-Service solution with a Payment Service Provider represents a major competitive advantage, enabling the optimisation of the customer experience and the automation of both incoming and outgoing payments.

With Xpollens’ Banking-as-a-Service platform, you benefit from API-based payment functionalities designed to accelerate your growth.
Whatever your PSPs, from onboarding new partners to fund distribution, collection and reconciliation, you can rely on the experience and guidance of teams that have already supported many companies and marketplaces, such as the ADEO platform or the B2B marketplace OVEO.

By selecting reliable and agile partners within the same group—such as the Payplug (PSP) and Xpollens (BaaS) duo from Groupe BPCE—you also gain simplicity and peace of mind when building a robust and scalable payment infrastructure. You are laying the foundations for a high-performing, sustainable marketplace in the online commerce market.