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Payment initiation APIs explained: How they work and when to use them

At a glance:

  • A payment initiation API is the technical interface that allows licensed third-party providers to initiate bank payments on behalf of the account holder with their consent.
  • The term can refer to two API layers: the PSD2 APIs that licensed providers use to connect to banks, and the Open Banking APIs that allow businesses to offer Pay by Bank payments through a PISP (Payment Initiation Service Provider).
  • Payment APIs are a broad category of tools used to support various payment methods, while payment initiation APIs specifically enable bank-to-bank Open Banking payments.
  • Common use cases for payment initiation APIs include account top-ups, failed-payment recovery, and reconciliation.

Manual bank transfers still create too much uncertainty in digital payment journeys. Customers drop off when they have to copy payment details into their banking app. Finance teams lose time matching incoming transfers to the right invoice or account. Product teams struggle to offer a bank-based payment experience that feels as simple as cards.

Payment initiation APIs solve this by turning bank transfers into guided, consent-based payment flows. Through a licensed provider, businesses can pre-fill payment details, redirect users to bank authentication, track payment status, and improve reconciliation.

However, not all providers are built the same, and the difference between a basic API and a full Open Finance partner shows up in your conversion rates, your audit trail, and how fast you can scale across markets. In this guide, we explain how payment initiation APIs work, when to use them, and how to choose the right provider.

Payment initiation API definition

Payment initiation APIs allow licensed third parties to initiate bank transfers from user accounts with their consent. Alongside account information services, they are governed by the European regulation PSD2 (soon to be PSD3).

In practice, “payment initiation API” can describe two connected layers. 

  • Banks expose interfaces that allow regulated payment initiation service providers (PISPs) to initiate transfers from accessible checking accounts. 
  • PISPs then expose their own APIs to businesses, enabling them to offer Pay by Bank journeys to customers without building and maintaining direct connections to every bank themselves.

Payment API vs. payment initiation API

Though critical for bank-based payments, a payment initiation API is not the same as a generic payment API or payment gateway. “Payment API” is a broad umbrella term used to describe credit card portals and other middlemen that facilitate card-based payments. 

A payment initiation API, on the other hand, is a specific tool used for direct bank-to-bank transfers. It is a technical interface that regulated providers can use to initiate account-to-account payments. Businesses that partner with licensed providers gain the ability to embed bank-based payments into digital journeys without the need for complicated in-house bank connection builds. 

Payment initiation vs. payment gateway vs. bank transfer

A generic payment API can support card payments, wallets, gateway logic, refunds, and broader payment acceptance logic. Payment initiation APIs have a narrower purpose of triggering bank-to-bank payments through Open Banking payment rails. They are not the same as a manual bank transfer, as much of the process can be done automatically once the account holder provides their consent. 

The key value of payment initiation APIs for businesses lies in orchestration, consent handling, status tracking, and a better overall UX. 

How does a payment initiation API work under PSD2/Open Banking?

  1. The business creates a payment request via API. In this request, the business sends details like amount, beneficiary, currency, payment reference, and redirect instructions. 
  2. The API provider connects the user to their bank. Providers handle the process of bank selection and redirecting users to the appropriate bank authentication flows. While PSD2 provides the regulatory framework and Open Banking technologies provide connectivity, the payment initiation API itself is what turns this process into a usable payment experience. 
  3. The bank authenticates and authorizes the transaction. Banks apply Strong Customer Authentication (SCA) as required by PSD2 within their own apps or web interfaces. 
  4. The provider retrieves the payment status. A payment initiation API provides updates to businesses on whether the payment is pending, accepted, rejected, completed, or failed.
  5. The business uses payment status updates for reconciliation. Providers give businesses the structured references and API updates necessary for matching payments automatically. 

Why businesses use payment initiation APIs

Businesses use PIS (Payment Initiation Services) to enable secure bank-to-bank payments with:

  • Lower transaction costs
  • Faster settlement
  • Reduced reliance on card networks
  • Strong customer authentication
  • Improved payment success rates

For a deeper look at these benefits and PIS use cases, read our dedicated Pay by Bank guide.

Key B2B use cases for payment initiation APIs

Payment initiation APIs support a wide range of business payment workflows by replacing manual bank transfer processes with guided, trackable payment journeys.

Wealth, investment, and crypto account top-ups

Funding accounts is a critical conversion point where users abandon the process. Instead of requiring customers to leave the platform and manually initiate a transfer through online banking, payment initiation APIs enable a guided bank payment experience within the funding journey. 

Lending and repayments

Recurring loan repayments are usually handled through SEPA Direct Debit (SDD), especially for scheduled collections. Payment initiation APIs, meanwhile, are more useful when that flow breaks down. 

For failed collections, overdue payments, or one-off payments, lenders can use Pay by Bank repayment links or embedded payment flows to let borrowers settle what they owe directly from their bank account. This gives them a simple, guided payment experience while helping lenders track payment status and reduce manual follow-ups. 

When payment initiation is combined with account information services (AIS), it offers even more value. By checking whether the borrower has sufficient funds before sending the payment request, lenders can trigger collection attempts at the right time and improve the chances of successful collection. 

Invoice payments and reconciliation

Many businesses still rely on manual invoice payments, which can be difficult to match against outstanding invoices. Payment initiation APIs streamline this process by including structured payment references and payment metadata, speeding up reconciliation and reducing the need for manual follow-up.

Payment initiation API vs. other payment models

Payment Initiation APICard / Payment GatewayManual Bank TransferSEPA Direct
TriggerUser consent via API + bank redirectCard details entered at checkoutUser manually copies details into bank appMerchant pulls funds via signed mandate
SpeedNear-instant (guided)InstantSlow / manualScheduled (days)
Cards involved?NoYesNoNo
Best forTop-ups, invoices, failed-payment recoveryRetail / e-commerce checkoutAd hoc, low-volume transfersRecurring, scheduled collections

Payment initiation API vs. other payment models

Payment initiation APIs differ from cards, manual bank transfers, and SEPA Direct Debit because they enable guided, bank-to-bank payments through Open Banking rails.

They are especially relevant for user-initiated flows such as account top-ups, invoice payments, failed payment recovery, and one-off repayments.

For a full comparison, read our guide to Pay by Bank vs other payment methods.

Are payment initiation APIs secure?

Payment initiation APIs are required to meet strict banking and regulatory security standards and are generally considered highly secure. To offer an API, PISPs must be licensed and supervised by financial authorities, as well as comply with strict audit and data protection requirements.

Key security features include:

  • Data exchanged between the business, PISP, and bank is protected with strong encryption protocols.
  • Payment requests rely on secure tokens and transaction-specific credentials rather than exposing sensitive banking information.
  • Users must authenticate directly with their bank according to SCA requirements, typically using biometric verification, one-time codes, or banking app approval.
  • Unlike card payments, account-to-account payment initiation does not require merchants to collect or store card numbers, CVVs, or expiry dates, which limits unauthorized fraud exposure.
  • Providers can access only the information necessary to process the payment and only with user consent.

No payment system is completely risk-free. However, most PIS security incidents involve social engineering tactics (such as phishing emails or spoofed calls) designed to trick users into authorizing payments, rather than vulnerabilities in the API technology itself.

What risk/compliance teams should verify

  • Is your payment initiation API provider regulated and licensed?
  • Does the API provide adequate authentication and access controls?
  • Does the API have comprehensive consent and audit trail management capabilities?
  • Can you view payment status and webhook reliability through the API?
  • Do you have the tools necessary for incident monitoring?
  • What is the API’s documentation quality?
  • How broad is the API’s bank coverage by country?
  • Can the API assist with reconciliation and reference handling?

Why companies use licensed third-party providers for PIS vs. building their own solutions

For most businesses, building a payment initiation solution in-house is both financially and operationally impractical. Maintaining connections with hundreds of banks and securing the necessary licenses requires significant investment, expertise, and time that most businesses simply don’t have to spare. 

Working with an established PIS provider like Powens offers advantages like:

  • Faster deployment
  • Lower upfront investment
  • Reduced maintenance requirements
  • Easier scalability across markets and banks
  • Less regulatory and compliance burden

Unless payment infrastructure is a core differentiator of your business, partnering with a licensed provider is typically the more efficient route for using a payment initiation API.

Overview of payment initiation API providers and how to choose

There are more than 400 licensed Open Banking providers across Europe, hundreds of which offer payment initiation APIs. So how do you go about choosing the right one?

Making the right pick comes down to the bank and service coverage you need. If you’re targeting the biggest EU markets like Spain, Germany, and Italy, a provider with comprehensive SEPA coverage like Powens makes a lot of sense as a strategic partner. 

If you only need a solution for payment initiation APIs, you’ll have more choice. But if you want a single provider to also help you with account initiation, data enrichment, categorization, reconciliation, and more, then the playing field narrows down quickly.

Once you filter your options according to services offered and coverage, you must study your options in more detail, looking at aspects like:

  • API availability and stability
  • Payment initiation success rate NOAS (No Action Status), the percentage of PIS sessions where a user fails to provide a definitive response (neither authorizing nor actively declining the transaction) before the session expires
  • Payment initiation end-to-end success rate: the percentage of payment initiations that result in a final successful completion out of the total number of attempts started
  • How many clients already use the solution, and the quality of their reviews and ratings

Why Powens is built for businesses that need more than a basic payment API

Payment initiation APIs can do much more than just trigger bank transfers. They are increasingly becoming a core component of processes like lending, collections, invoice payments, reconciliation, and account funding.

The greatest value comes when payment initiation is combined with AIS. Businesses can connect payment flows with bank account data, balances, transaction history, and payment status to create smoother user journeys, improve collection timing, and simplify reconciliation.

Choosing the right partner is critical. Businesses need a platform that can both provide the connections needed for Pay by Bank payments and the top-notch security expected from a licensed provider.

Powens is a regulated Open Finance platform that combines payment initiation with financial data connectivity, helping businesses build seamless bank-to-bank payment journeys across Europe.

Get in touch today to learn more.