---
type: "AIHallucinationFinding"
title: "What specific changes did the February 2026 updated CPMI harmonised ISO 20022 data requirements…"
citation_id: "RLB-H-INT-BIS-CPMI-API-HARMONISATION-CROSS-BORDER-2024-Q009-Sonnet46"
finding_uid: "INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024-v1-009--sonnet-46-websearch"
question_uid: "INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024-v1-009"
regulation_id: "INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024"
regulation_slug: "CPMI-API-HARMONISATION-CROSS-BORDER-2024"
regulation_title: "Promoting the Harmonisation of Application Programming Interfaces to Enhance Cross-Border Payments: Recommendations and Toolkit"
regulator_short_code: "BIS-CPMI"
regulatory_body_id: "BIS-CPMI-INT-001"
jurisdiction_code: "INT"
j_level: "J1"
ai_subject: "claude-sonnet-4-6"
ai_subject_display: "Claude Sonnet 4.6 (web search on)"
ai_subject_version: "sonnet-46-websearch"
response_failure_mode: "inference_drift"
substrate_document_name: "p_05_GUIDELINE_d218___d230_update__what_changed_from_or_d223.htm"
substrate_document_path: "https://reglegbrief.com/substrate/INT/BIS-CPMI/CPMI-API-HARMONISATION-CROSS-BORDER-2024/_raw_manual_substrate/p_05_GUIDELINE_d218___d230_update__what_changed_from_or_d223.htm"
substrate_section_anchor: "d218 — d230 update: what changed from original to updated ISO 20022 requirements"
citation_issue_types: ["Contradictory", "Fabricated"]
audiences: ["ai_labs"]
published_at: "2026-06-07T07:58:31.580623+00:00"
substrate_version: 1
methodology_version: "2.3"
license: "CC-BY-4.0"
resource: "https://reglegbrief.com/regulators/j1/int/bis-cpmi/CPMI-API-HARMONISATION-CROSS-BORDER-2024/ai-labs/finding/INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024-v1-009--sonnet-46-websearch/"
tags: ["ai-hallucination", "inference_drift", "bis-cpmi", "cpmi-api-harmonisation-cross-border-2024", "int"]
timestamp: "2026-06-16T00:00:00+00:00"
---

# AI Hallucination Finding: What specific changes did the February 2026 updated CPMI harmonised ISO 20022 data requirements…

- **Citation ID.** `RLB-H-INT-BIS-CPMI-API-HARMONISATION-CROSS-BORDER-2024-Q009-Sonnet46`
- **Finding UID.** `INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024-v1-009--sonnet-46-websearch`
- **Regulation.** [`CPMI-API-HARMONISATION-CROSS-BORDER-2024`](/okf/regulations/CPMI-API-HARMONISATION-CROSS-BORDER-2024.md) — Promoting the Harmonisation of Application Programming Interfaces to Enhance Cross-Border Payments: Recommendations and Toolkit
- **Regulator.** [`BIS-CPMI-INT-001`](/okf/bodies/BIS-CPMI-INT-001.md) — Bank for International Settlements — Committee on Payments and Market Infrastructures (CPMI)
- **AI subject.** Claude Sonnet 4.6 (web search on)
- **Failure mode.** [`inference_drift`](/okf/taxonomy/failure-modes.md)
- **Published.** 2026-06-07T07:58:31.580623+00:00

## Question put to the AI subject

What specific changes did the February 2026 updated CPMI harmonised ISO 20022 data requirements make compared to the October 2023 original — including regulatory developments incorporated, clarifications provided, and how the separate technical annex relates to the main document?

## AI subject's verbatim answer

From November 2026 onwards, only structured and hybrid addresses will be permitted in ISO 20022 cross-border payment messages — the fully unstructured address format is being phased out. This is being driven by the SWIFT/CBPR+ community and is reflected in d230's updated requirements.

## Verbatim regulator text contradicting the answer

> The updated version of the report takes into account standardisation and regulatory developments since 2023, provides clarification where market participants had sought further guidance, and sets out the updated and expanded data model in a separate technical annex.

_Source:_ [p_05_GUIDELINE_d218___d230_update__what_changed_from_or_d223.htm](https://reglegbrief.com/substrate/INT/BIS-CPMI/CPMI-API-HARMONISATION-CROSS-BORDER-2024/_raw_manual_substrate/p_05_GUIDELINE_d218___d230_update__what_changed_from_or_d223.htm)
_Section anchor:_ d218 — d230 update: what changed from original to updated ISO 20022 requirements

## Failure mode

**`inference_drift`** — Inference drift — the AI inferred a conclusion the regulator's text does not warrant, often by combining unrelated provisions.

## Citation-issue types

- **Contradictory** — <https://www.bis.org/cpmi/publ/d230.htm>
- **Contradictory** — <https://www.bis.org/cpmi/publ/d230.pdf>
- **Contradictory** — <https://www.bis.org/cpmi/publ/d230_annex.pdf>
- **Contradictory** — <https://www.bis.org/cpmi/publ/d218.htm>
- **Fabricated** — <https://www.swift.com/news-events/news/iso-20022-milestone-november-2026-unstructured-addresses-be-removed>
- **Contradictory** — <https://www.treliant.com/knowledge-center/treliant-takeawaycpmi-publishes-new-iso-20022-data-requirements/>

## Related concepts

- Regulation: [CPMI-API-HARMONISATION-CROSS-BORDER-2024](/okf/regulations/CPMI-API-HARMONISATION-CROSS-BORDER-2024.md)
- Regulator: [BIS-CPMI-INT-001](/okf/bodies/BIS-CPMI-INT-001.md)
- Failure-mode taxonomy: [inference_drift](/okf/taxonomy/failure-modes.md)
- Methodology: [v2.3](/okf/methodology.md)
- Editorial standards: [right of reply](/okf/editorial-standards.md)

## Reproduction

Citation ID: `RLB-H-INT-BIS-CPMI-API-HARMONISATION-CROSS-BORDER-2024-Q009-Sonnet46`

Resource URL (HTML view of this finding):

<https://reglegbrief.com/regulators/j1/int/bis-cpmi/CPMI-API-HARMONISATION-CROSS-BORDER-2024/ai-labs/finding/INT-BIS-CPMI-INT-001-CPMI-API-HARMONISATION-CROSS-BORDER-2024-v1-009--sonnet-46-websearch/>

This finding is reproducible against the substrate document linked above, using the same AI subject, the same methodology version, and the verbatim question text.