Report

Phase 4: Illegal Gambling Index – Technical Report

The Gambling Commission’s technical report detailing the development of the Illegal Gambling Index.

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Published
5 November 2026

Last updated
5 November 2026 - Changes

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Contents

• Phase 4: Illegal Gambling Index – Technical Report

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• Executive summary
• Introduction
• Overview of approach
• • Timeline of the approach
  • Strengths and limitations
• Statement development
• • Statement development during Phase 1
  • Statement development during Phase 2
  • The final statements for the GSGB
• Development of the analysis approach
• • Introduction to the development of the analysis approach
  • Development of the illegal gambling index
  • Flexing the index for the GSGB
  • Recommendations for future use
• Commission modification of the index
• Final illegal gambling index
• • Final strength ratings for the index
  • Calculating the index
  • Reporting the findings
• Conclusions and next steps
• Appendices
• • Appendix A - Quota and weighting targets for representative online survey
  • Appendix B - Authorship of this report

Conclusions and next steps

This report signifies the conclusion of a multi-phase series of Consumer Voice research projects conducted by Yonder, each phase of which has been instrumental in helping to build a complete picture of consumer engagement with illegal gambling websites. With the addition of this workstream, the Commission has moved from a position of limited knowledge of the nature of the market to one of more robust statistical measurement of the consumer engagement within it.

This journey represents a significant milestone in adding to the Commission’s Illegal gambling and crime Evidence Roadmap, supporting the development of a robust evidence base on participation in online illegal gambling in Great Britain. This was only made possible by the pursual of a robust, evidence-led understanding of this complex and often hidden market. The decision to develop the Illegal Gambling Index was one that came out of requiring a comprehensive and adaptable metric through which the Commission can monitor consumer engagement with illegal gambling websites. The Illegal Gambling Index has therefore been intentionally designed to be flexible and may therefore evolve over time as further evidence and data becomes available.

As the gambling landscape changes, new indicators may be added, and existing indicators may be revised or removed. Accordingly, the scoring framework may be recalculated to ensure the index remains robust, relevant, and capable of accurately capturing consumer engagement with illegal websites.

Next steps

In addition to having the capability to monitor overall consumer engagement with illegal gambling websites, the Commission aims to track the different persona groups within this population. These personas were identified and explored in depth through previous phases of this strand of research. Most recently, Phase 3 provided clear metrics through which prevalence of some of the persona groups can be identified using the Gambling Survey for Great Britain (GSGB). Building on the existing GSGB illegal gambling questions, an additional suite of questions developed within Phase 3 will be incorporated into the GSGB 2027, Wave 1.

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Appendices - Illegal gambling technical report

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Last updated: 5 November 2026

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