GLOBAL PAYMENTS KNOWLEDGEISO 20022 / SWIFT / SEPA / MT / MX
FOLLOW THE PAYMENT

Open-banking payment initiation

Maya Chen pays at a merchant checkout through Larkpay, a fictional licensed payment institution acting as a payment initiation service provider (PISP). Larkpay asks Bank Alfa to send a SEPA credit transfer to Northstar Bank. (SYNTHETIC / TRAINING ONLY)

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Open-banking payment initiation — interactive diagramMaya Chen pays at a merchant checkout through Larkpay, a fictional licensed payment institution acting as a payment initiation service provider (PISP). Larkpay asks Bank Alfa to send a SEPA credit transfer to Northstar Bank. (SYNTHETIC / TRAINING ONLY) The full step-by-step description follows this diagram as text.1. Consent2. Init API3. Apply SCA4. Authenticate5. DR payer6. pacs.0087. Clear8. Settlement9. CR creditor
STEP 1 / 9MESSAGE

Maya consents at the merchant checkout

Maya Chen (payer) → Larkpay (PISP)

Instead of typing card details, Maya chooses to pay by bank. She gives Larkpay consent to start a single payment of EUR 42.50 from her account — consent is for this one payment, not open-ended access.

Step 1 of 9: Maya consents at the merchant checkout

  1. 01Message
    Maya consents at the merchant checkoutMaya Chen (payer) → Larkpay (PISP)
  2. 02Message
    Larkpay initiates the payment via Bank Alfa's APILarkpay (PISP) → Bank Alfa (ASPSP) · Payment-initiation API request
  3. 03Processing
    Bank Alfa applies strong customer authenticationBank Alfa (ASPSP)
  4. 04Message
    Maya authenticates with her bankMaya Chen (payer) → Bank Alfa (ASPSP)
  5. 05Posting
    Bank Alfa validates and debits MayaBank Alfa (ASPSP)
  6. 06Message
    Bank Alfa sends a SEPA credit transferBank Alfa (ASPSP) → Clearing & settlement mechanism · pacs.008
  7. 07Clearing obligation
    The CSM clears the transferBank Alfa (ASPSP) → Northstar Bank (creditor agent)
  8. 08Settlement
    The transfer settles between the banksBank Alfa (ASPSP) → Northstar Bank (creditor agent)
  9. 09Posting
    Northstar Bank credits the merchantNorthstar Bank (creditor agent)
MESSAGECLEARING OBLIGATIONSETTLEMENTPOSTING
Full step-by-step text (works without JavaScript)
  1. 01Message
    Maya consents at the merchant checkoutMaya Chen (payer) → Larkpay (PISP)

    Instead of typing card details, Maya chooses to pay by bank. She gives Larkpay consent to start a single payment of EUR 42.50 from her account — consent is for this one payment, not open-ended access.

  2. 02Message
    Larkpay initiates the payment via Bank Alfa's APILarkpay (PISP) → Bank Alfa (ASPSP) · Payment-initiation API request

    As a payment initiation service provider, Larkpay does not hold Maya's money. It calls Bank Alfa's open-banking API — the account servicer, or ASPSP — to set up the credit transfer Maya consented to.

  3. 03Processing
    Bank Alfa applies strong customer authenticationBank Alfa (ASPSP)

    Bank Alfa, not Larkpay, authenticates Maya. It applies strong customer authentication (SCA) — typically a redirect or app check with two independent factors — because only the account-holding bank may authorise moving her money.

  4. 04Message
    Maya authenticates with her bankMaya Chen (payer) → Bank Alfa (ASPSP)

    Maya approves the payment directly with Bank Alfa — in its app or via a redirect — proving it is really her. Larkpay never sees her banking credentials; it only learns whether authentication succeeded.

  5. 05Posting
    Bank Alfa validates and debits MayaBank Alfa (ASPSP)

    With SCA passed, Bank Alfa checks funds and books the EUR 42.50 debit against Maya's account. Her money has left her account, but nothing has yet moved between the banks.

    • DR Maya Chen's current account at Bank AlfaEUR 42.50
  6. 06Message
    Bank Alfa sends a SEPA credit transferBank Alfa (ASPSP) → Clearing & settlement mechanism · pacs.008

    The initiated payment becomes an ordinary interbank SEPA Instant credit transfer. Bank Alfa submits a pacs.008 to the clearing and settlement mechanism, addressed to Northstar Bank. Open banking started the payment; the SEPA rails carry it.

  7. 07Clearing obligation
    The CSM clears the transferBank Alfa (ASPSP) → Northstar Bank (creditor agent)

    The clearing and settlement mechanism validates the pacs.008 and calculates the obligation between the two banks — who owes whom — before any money moves.

    Clearing produces an obligation. The banks do not have their money yet — that happens at settlement.

  8. 08Settlement
    The transfer settles between the banksBank Alfa (ASPSP) → Northstar Bank (creditor agent)

    The obligation settles across the banks' settlement accounts in central bank money. Only now has EUR 42.50 truly moved from Bank Alfa to Northstar Bank.

    • DR Bank Alfa settlement accountEUR 42.50
    • CR Northstar Bank settlement accountEUR 42.50
  9. 09Posting
    Northstar Bank credits the merchantNorthstar Bank (creditor agent)

    Northstar Bank credits the merchant's account and confirms receipt. The checkout completes: Maya consented, her bank authenticated and debited her, and the money settled over the SEPA rails.

    • CR Merchant's account at Northstar BankEUR 42.50

What this simplifies: One payment-initiation call over a generalised open-banking API, then a single SEPA Instant credit transfer through one CSM. Real deployments vary the API standard, the SCA journey (redirect vs decoupled) and add reconciliation. Larkpay is fictional; the amount is illustrative.

Sources for this flow3
  1. Official requirement

    PSD2 and the RTS on strong customer authentication and secure communicationEuropean Banking Authority · PSD2 + RTS on SCA and secure communication

    Governs open banking access in the European Union, including payment initiation and account information services offered by third-party providers, and the requirement for strong customer authentication. · Checked 2026-07-13

    Referenced from the European Banking Authority's public summaries, guidelines, and technical standards on payment services.

  2. Scheme-specific rule2025 version 1.1 (EPC125-05)

    2025 SEPA Credit Transfer rulebookEuropean Payments Council

    Governs the SEPA Credit Transfer scheme: participant obligations, datasets, time cycles, and r-transaction rules for euro credit transfers. · Effective 2025-10-05 · Checked 2026-07-12

    Version 1.1 replaced version 1.0 at publication on 5 October 2025 and is stated to remain in effect up to 21 November 2027. It moves the date from which the unstructured address format is no longer permitted to 15 November 2026.

  3. Simplified educational illustration

    Payments Signal editorial teaching modelsPayments Signal

    This site's own simplified teaching models. · Checked 2026-07-12

    What this simplifies: One PISP, one ASPSP, one CSM and a single settlement cycle. API message shapes are generalised, and refund or reconciliation handling is omitted; Larkpay is a fictional payment institution and the amount is illustrative.

    Used wherever diagrams, scenarios, figures, or example values are didactic constructions rather than sourced facts; every such use carries a simplifications disclosure. All people, companies, banks, and list entries in examples are fictional.

COMMUNITY SIGNAL

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