Case Studies

High-Profile Non-Compliant Submissions

Examples of UK Main Market investment trusts filing XHTML documents without required iXBRL tagging

Analysis Date
December 2025
Regulatory Framework
DTR 4.1.14R
Section 1

Background

The following examples demonstrate a systemic compliance gap in the NSM. These are submissions from well-known UK Main Market listed investment trusts managed by major asset managers that have filed XHTML documents without the required Inline XBRL tagging.

Key Finding

Many of these files have .xhtml extensions, which may give the appearance of compliance. However, upon inspection, they are PDF-to-HTML conversions created by tools like pdf2htmlEX. These contain embedded fonts and visual layouts but no machine-readable XBRL data.

Each example below includes:

Example 1

The City of London Investment Trust plc

Filing Details

One of the UK's oldest investment trusts, established 1891. Managed by Janus Henderson Investors.

Company The City of London Investment Trust plc
LEI 213800F3NOTF47H6AO55
File Type PDF Conversion
Filing Date 15 October 2025
NSM Link View on NSM
Cached Copy reports.ticker.app
Data Extractable No - Visual only

Technical Analysis

Despite the .xhtml extension, this file was created using pdf2htmlEX. The file contains embedded WOFF fonts and absolute CSS positioning but zero iXBRL markup.

Example 2

The Baillie Gifford Japan Trust PLC

Filing Details

Major Japanese equity investment trust managed by Baillie Gifford, one of Scotland's largest investment managers.

Company The Baillie Gifford Japan Trust PLC
LEI 54930037AGTKN765Y741
File Type PDF Conversion
Filing Date 6 November 2025
NSM Link View on NSM
Cached Copy reports.ticker.app
Data Extractable No - Visual only
Example 3

Schroder UK Mid Cap Fund plc

Filing Details

UK mid-cap equity investment trust managed by Schroders, one of the UK's largest asset managers.

Company Schroder UK Mid Cap Fund plc
LEI 549300SOEWCYZTK2SP87
File Type PDF Conversion
Filing Date 27 November 2025
NSM Link View on NSM
Cached Copy reports.ticker.app
Data Extractable No - Visual only
Example 4

Fidelity Asian Values PLC

Filing Details

Asian equity investment trust managed by FIL Investment International (Fidelity).

Company Fidelity Asian Values PLC
LEI 54930094CXNYINSNOQ96
File Type PDF Conversion
Filing Date 26 October 2025
NSM Link View on NSM
Cached Copy reports.ticker.app
Data Extractable No - Visual only
Example 5

Schroder Japan Trust plc

Filing Details

Japanese equity investment trust managed by Schroders.

Company Schroder Japan Trust plc
LEI 549300SSPK3AXNJOC673
File Type PDF Conversion
Filing Date 8 October 2025
NSM Link View on NSM
Cached Copy reports.ticker.app
Data Extractable No - Visual only
Section 2

Pattern Analysis

Common Characteristics

These examples share several characteristics:

  • All are UK Main Market listed investment trusts
  • All are managed by major, reputable asset managers (Janus Henderson, Baillie Gifford, Schroders, Fidelity)
  • All filed documents with .xhtml extensions that are actually pdf2htmlEX conversions
  • All filings are from late 2025, well after the ESEF mandate came into force

This pattern suggests the issue is not isolated to individual issuers but may relate to common service providers or filing workflows used across the investment trust sector.

Section 3

Implications

Impact of Non-Compliance

Consequences of filing PDF conversions instead of properly tagged iXBRL documents

Stakeholder Impact
Retail Investors Cannot use automated tools or AI assistants to extract and compare financial data across investment trusts
Data Providers Must resort to manual data entry or OCR, introducing errors and delays
Regulators Cannot perform automated market-wide analysis or supervision of the investment trust sector
Academic Research Large-scale financial research on UK investment trusts hampered by inconsistent data availability
Market Integrity Creates information asymmetry favouring those with manual extraction resources

Regulatory Concern

These companies are subject to DTR 4.1.14R, which requires Annual Financial Reports to be prepared in XHTML with valid Inline XBRL tagging. Filing PDF conversions with .xhtml extensions does not satisfy this requirement, regardless of how the file renders visually in a browser.

Section 4

How to Verify Compliance

Anyone can verify whether an XHTML file contains valid iXBRL tagging by examining the source code. A compliant file must contain:

Compliant iXBRL File Contains

  • xmlns:ix namespace declaration
  • xmlns:xbrli namespace declaration
  • <ix:nonFraction> elements (tagged numbers)
  • <ix:nonNumeric> elements (tagged text)
  • <xbrli:context> definitions
  • References to IFRS or UKSEF taxonomy

PDF Conversion Contains

  • <!-- Created by pdf2htmlEX -->
  • Embedded @font-face declarations
  • Base64-encoded WOFF font data
  • Absolute CSS positioning
  • No XBRL namespaces
  • No tagged financial data

You can view the source of any XHTML file on the NSM by:

  1. Opening the document in a web browser
  2. Right-clicking and selecting "View Page Source"
  3. Searching for xmlns:ix - if not found, the file lacks iXBRL
  4. Searching for pdf2htmlEX - if found, it's a PDF conversion

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