SOURCE 0 — THE ENDOGENOUS AUDIT PARADOX IN THE PAYMENT SERVICES REGULATION (PSR)
Author: Jean-François ELSEN (Senior Forensic Auditor · Judicial Specialist in Digital Evidence · DGSA)
Location: Brussels – Charleroi, Belgium
Organization: Jean-François ELSEN ·jfelsen.com
Classification: Authoritative Public Release · July 2026
Audience: C-Suite Executives, Boards of Directors, Regulators, Supervisory Authorities, Legal Departments, CISOs, Compliance Officers, AI Governance Architects, Forensic Analysts, Critical Infrastructure Operators, Public Authorities
Series: SOURCE 0 Doctrine Series
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The EU Payment Services Regulation, referred to by the acronym PSR — not to be confused with the UK Payment Systems Regulator, which shares the same acronym but has no connection to this text — now expressly codifies what SOURCE 0 doctrine calls the Endogenous Audit Paradox: a system cannot serve as independent proof of its own reliability. Article 55, paragraph 2, of the PSR's final compromise text, published on 23 April 2026, provides that the fact a payment transaction was authenticated, including where applicable through strong customer authentication, is not in itself necessarily sufficient to prove either that the transaction was authorised by the payer, or that the payer acted fraudulently or with gross negligence. This rule is not new in principle — it extends Article 72, paragraph 2, of the 2015 PSD2 directive — but it is new in scope, since it names strong customer authentication itself as insufficient on its own for the first time. French case law from 2026 already provides a concrete confirmation, ahead of the regulation's entry into force.
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1. THE REVERSAL OF THE BURDEN OF PROOF UNDER PSD2
Directive (EU) 2015/2366, known as PSD2, already laid down at its Article 72 the principle that still structures the bulk of banking litigation over disputed transactions today. Where a payment service user denies having authorised an executed transaction, the burden of proof falls on the payment service provider: it is for the provider to show that the transaction was authenticated, duly recorded, entered into the accounts, and not affected by a technical breakdown or other deficiency.
Paragraph 2 of that article added a decisive precision, one that SOURCE 0 doctrine treats as among the rare direct legislative anchors for what it calls the Endogenous Audit Paradox: the use of a payment instrument recorded by the provider does not, in itself, suffice to prove either that the transaction was authorised by the payer, or that the payer acted fraudulently or with gross negligence. The provider had to supply further supporting evidence, without the text ever specifying its nature or format.
This rule is transposed into French law at Article L. 133-18 of the Code monétaire et financier, which requires the provider to refund the payer immediately in the event of an unauthorised transaction, unless it can demonstrate gross negligence within the meaning of Article L. 133-19.
2. CONFIRMATION IN THE PSR'S FINAL COMPROMISE TEXT
The PSR, whose interinstitutional negotiations concluded with the publication of the final compromise text on 23 April 2026, carries this architecture forward, reformulating it at Article 55, titled "Evidence on authorisation and execution of payment transactions." Paragraph 1 of that article places the burden of proof on the payment service provider, who must show that the transaction was authorised, accurately recorded, entered into the accounts, and not affected by a technical breakdown or other deficiency of the service provided.
This paragraph is not a mere restatement. Unlike the directive it replaces, the regulation applies directly across all Member States without national transposition — putting an end to the interpretive divergences that the Commission identified in its evaluation of PSD2, particularly on the relationship between technical authentication and legal authorisation.
3. THE EXPLICIT EXTENSION TO STRONG CUSTOMER AUTHENTICATION
Paragraph 2 of Article 55 constitutes the most significant normative contribution of this regulation to the SOURCE 0 thesis. It provides that the fact a payment transaction was authenticated — including, where applicable, through strong customer authentication — accurately recorded, entered into the accounts, and not affected by a technical breakdown or other deficiency of the service provided, does not necessarily suffice, in itself, to prove either that the transaction was authorised by the payer, or that the payer acted fraudulently or failed, intentionally or through gross negligence, to fulfil one of the obligations incumbent on them.
This wording does not simply carry forward Article 72 of PSD2: it explicitly names strong customer authentication, whereas the 2015 text referred only to the generic use of a recorded payment instrument. The regulation adds, at paragraph 2a, a procedural safeguard absent from PSD2: before concluding that a user authorised a transaction, or acted fraudulently or with gross negligence, the provider must invite them to supply information about the circumstances of the disputed transaction and take it into account in its assessment. A user's failure to respond cannot, on its own, justify a finding of fraud or gross negligence, and the user is not expected to produce information beyond what they could reasonably be expected to hold.
A recital in the compromise text sets out the rationale: the means by which consent may be assumed to have been given have become more complex to identify, since fraudsters can now take control of the entire consent and authentication process, including strong customer authentication itself. A transaction may therefore have been authenticated in circumstances where authorisation was obtained on manipulated premises, affecting the integrity of the consent.
4. CONFIRMATION BY FRENCH CASE LAW
What the regulation codifies for 2026-2028, French courts have already found in 2026, on the basis of the law currently in force.
The Tribunal judiciaire de Nice, in a judgment of 10 February 2026 (4th civil chamber, case n° 24/00689), rejected a bank's argument that its client must have "necessarily, if unwittingly, been an actor" in the fraud by disclosing her confidential data. The court held that the bank produced no concrete proof of that disclosure, and that it could not be inferred from the mere fact that the payment instrument and associated personal data had in fact been used — that is, from the mere fact that strong customer authentication had technically functioned.
The Tribunal judiciaire de Rodez, on 12 February 2026 (case n° 24/01535), stated the finding even more directly, noting that the bank "in no way established either the absence of any deficiency in its secure authentication device, or the client's gross negligence." The Cour d'appel de Paris, on 2 April 2026 (Pôle 4, Chamber 9 A, case n° RG 25/00442), confirmed on appeal that a technically successful authentication does not prove the client's consent, in a case where the first-instance judge had initially placed the burden of proving the absence of consent on the client.
These three rulings, handed down independently of one another, in different courts, on distinct facts, converge on the same finding that Article 55, paragraph 2, of the PSR has just codified: the technical validation of an authentication does not, by itself, constitute legal proof of authorisation.
5. WHAT THE TEXT LEAVES UNRESOLVED
Article 55 imposes a heightened burden of proof on the provider, but says nothing about the nature, format, or retention conditions of the elements it must produce to discharge it. Commission Delegated Regulation (EU) 2018/389, which currently sets the technical requirements for strong customer authentication, will be replaced by a new regulatory technical standard that the European Banking Authority has yet to draft, due one year after the regulation's entry into force. At this stage, neither the exact content of that future standard, nor the format in which a provider will have to present proof of compliance to a court, has been fixed.
This is the same difficulty SOURCE 0 doctrine has already documented in the field of anti-money laundering: a text can reverse the burden of proof without ever defining what constitutes admissible, opposable evidence.
6. THE SOURCE 0 RESPONSE
What Article 55 of the PSR and the converging French case law establish is a duty of proof without an architecture of proof. The provider must show that authentication was free of deficiency and that consent was not obtained on manipulated premises — but the text prescribes no independent mechanism capable of establishing, in an opposable manner, the state of the system at the precise moment of the disputed transaction.
SOURCE 0 answers this gap with a pre-execution cryptographic attestation architecture, structurally independent from the system it documents, timestamped under a dual RFC 3161-compliant qualified protocol and deposited with a huissier de justice belge, establishing date certaine under Book 8 of the Belgian new Civil Code. This mechanism does not replace strong customer authentication: it documents, independently and prior to any dispute, the state of the technical device at the moment the transaction took place — answering precisely what Article 55, paragraph 2, of the PSR requires without, by itself, making possible.
CLOSING AXIOM
The law does not require material truth. It requires proof of diligence. SOURCE 0 seals that diligence.
REFERENCE NOTE
SOURCE 0 is a registered Benelux trademark, BOIP/OBPI n° 1548293, filed 6 May 2026. This article draws on the final compromise text of the Payment Services Regulation (PSR), Council of the European Union document ST-8221/26 of 17 April 2026; on Directive (EU) 2015/2366 (PSD2); on Commission Delegated Regulation (EU) 2018/389; and on the judicial decisions cited, each identified by court, date, and case number. This article was written by Jean-François ELSEN, evidentiary engineering.
REGULATORY NOTICE
This article is provided for informational and doctrinal purposes only. It does not constitute legal advice, a legal opinion, or a guarantee of application to any particular situation. The PSR text cited in this article is a compromise text still undergoing formal adoption by the European Parliament and the Council; its article numbering and final content remain subject to drafting adjustments before publication in the Official Journal of the European Union. Any application to a specific case requires independent verification of the law in force at the relevant date.
