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AI Labs · Last updated 7 Jun 2026 · methodology vv2.3 · Hallucination Register

Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON

RLB Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47
What the RLB Specialist Panel found

Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON

  • Question (paraphrased to protect IP): What percentage of faster payment systems and RTGS systems currently use ISO 20022 messaging, according to CPMI monitoring data?
  • AI's response: "approximately 79% of both real-time gross settlement (RTGS) systems and fast payment systems (FPS) had either already implemented ISO 20022 or had concrete plans to do so"
  • Regulator's text: Andrew Bailey speech (12 March 2026): "more than three-quarters of faster payment systems and approaching half of RTGS systems now use ISO 20022."
  • Why the AI went wrong: The regulator's record gives two distinct figures, faster payment systems and RTGS systems are separately characterised, with RTGS adoption described as approaching half. The model collapsed these into a single blended percentage applied to both system types simultaneously. The 79% figure appears to be an internally-reconstructed composite; it matches neither the faster-payment nor the RTGS figure in the official record. The failure is silent, the model expressed no uncertainty about the figure it produced.
  • Cited source(s):
Impact for this audience

This failure implicates the training corpus's handling of subcategory-level numeric claims from official-speech channels. The model produced a single blended 79% figure where the regulator's March 2026 speech gives two distinct values — one for faster payment systems and a substantially lower one for RTGS. This suggests the speech content either was not retrieved or was compressed during ingestion in a way that averaged across the two system-type categories. If your eval suite tests adoption-rate questions at the aggregate level only, this failure is invisible; the gap is specifically at subcategory resolution.

References — raw findings (per AI model)
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Cite this finding

Each finding has a stable Citation ID (RLB-F-… for aggregated case-study findings, RLB-H-… for raw per-model hallucinations) — like a DOI, the ID always resolves to the canonical finding even if URLs change.

RLB Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47
Plain text Download 
RegLeg Specialist Panel (2026). "Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON — AI Labs." Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47. RegLegBrief AI Hallucination Research, published 2026-06-07. https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-006--opus-47-websearch/
APA 7th edition Download 
RegLeg Specialist Panel. (2026). Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON [Hallucination finding RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-006--opus-47-websearch/
Bluebook / OSCOLA (US + UK legal) Download 
RegLeg Specialist Panel, Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON [RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47], RegLegBrief AI Hallucination Research (June 07, 2026), https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-006--opus-47-websearch/.
BibTeX Download 
@misc{reglegbrief_RLB_H_INT_BIS_CPMI_ISO_20022_HARMONISATION_UPDATED_2026_Q006_Opus47,
  author    = {RegLeg Specialist Panel},
  title     = {Finding on 'Q006 Probe' for Claude Opus 4.7 with web search ON},
  year      = {2026},
  publisher = {RegLegBrief AI Hallucination Research},
  note      = {Hallucination finding Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q006-Opus47},
  url       = {https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-006--opus-47-websearch/}
}
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