Why is it so hard to measure the size of the illegal gambling market?

Our Director of Research and Statistics Ben Haden reflects on the final in a series of reports exploring the issue of illegal online gambling, where we set out the challenge of measuring the scale of illegal gambling and present opportunities to make progress.

Posted 6 November 2025 by Ben Haden

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Today’s report focuses on the challenges of estimating the size of the illegal online gambling market. Improving understanding of the size of this market is important. It will help us target resources and encourage a more informed debate about how we can best tackle this threat to consumers and legitimate businesses.

But measuring the size of the illegal gambling market is difficult. That’s not an excuse. It is the reality of attempting to objectively measure an activity that is largely hidden. Robust and reliable data is limited, and assumptions must be made to fill the gaps. The same challenge is experienced by Government Departments responsible for estimating the financial impact of other areas of criminal activity – for example the tax gap associated with illegal tobacco.

Last month, in Report Two, we published the data we have collected on consumer engagement with illegal websites. This provided useful insight into trends in estimated use of this market. These findings, however, came with caveats and uncertainty. As a public body, with a responsibility for generating reliable and credible statistics, it is vital that we communicate uncertainty associated with our research and issue health warnings where necessary.

The central challenge to estimating the size of the illegal market is the number of additional assumptions that must be made to convert estimates of levels of engagement into estimates of expenditure. The effect of this is that margins for error become compounded and exaggerated – leading to a situation where we do not have sufficient confidence that results will offer meaningful insight.

Where next…?

Although our latest report sets out the challenges – our conclusion is that continuing work to measure and understand this work is worth pursuing. In Report Three we set out the myriad of disruption tactics and enforcement activities we are undertaking to make it difficult to provide illegal gambling at scale to consumers in Great Britain. Measuring the scale of illegal gambling will help tell us if our work is having an impact and demonstrates to other stakeholders the need for action – which will involve other sectors (digital industries, financial services), international partners (particularly other regulators) and government.

We have set out areas of work to focus upon. By breaking down the challenge into its constituent parts, it is possible to see a pathway to making an estimate that is fit for purpose. Getting there will also need input from operators – data on the legal market will help us strengthen assumptions and update our evidence base. We are looking forward to further conversations to clarify what we need and how operators can help.

While the exercise of trying to understand the macro-metric of the size of the illegal market is important, the generation of trend data – and insight into specific websites to target disruption activity, is arguably even more vital. We are pleased we are now able to better understand these trends and supply key operational data to our Enforcement Team.

Reflections on what we have learnt so far

This report provides a chance to recap and reflect on what we have learnt and shared through the series of reports we published this autumn:

• like many other commodities, the gambling market has always had, and will continue to experience, an illegal component. As with other illegal markets, it is constantly changing and requires action from multiple partners to tackle. The Commission’s role is to make it as difficult as possible for this illegal market to operate at scale. This is a significant challenge as both consumer behaviour and illegal operators will adapt
• consumer motivations for using illegal websites and other illegal gambling opportunities are varied – there is no single factor driving this activity
• consumers that use illegal web sites don’t always realise they are doing so. Although legal and illegal is a clearcut definition to us as a regulator – consumer perceptions are more fluid
• not all expenditure by British consumers in the illegal market should be seen through the lens of a ‘loss’ to the legal market. It appears that many consumers are self-excluded – and therefore unable to gamble in the regulated market. The risk of harm to these consumers is significant, but this is not a legitimate revenue stream for the legal market which has been deprived from responsible gambling operators
• consumers also use the illegal market because they have had their gambling opportunities restricted for commercial reasons in the legal market
• whilst we recognise that we have not collected data for all illegal gambling opportunities – we have not seen evidence of sustained growth in engagement with websites where data has been collected. This doesn’t mean we don’t see a serious problem that needs addressing, but it does call into question the realism of some of the claims made about persistent and uncontrolled growth in engagement with this market
• we continue to develop tools and tactics to take effective risk-based disruption action against illegal gambling. We have set out the wide variety of disruption techniques already in our toolkit, and the work we are doing resource permitting, to expand and strengthen the action we can take. International and cross-industry collaboration is making it difficult for illegal gambling to operate at scale in Great Britain.

Conclusions

Consumers expect regulation in the legal market that offers appropriate levels of protection and fairness. Licensees expect regulation to be proportionate and consistently applied. Lowering regulatory standards is not a credible way to tackle the risks of the illegal market.

We hope that our four recent reports have helped all interested stakeholders to understand this issue, and our response to it, in greater detail. Although this is our last publication of this autumn series, it is not the end of the story. Our next steps will include further research, data collection and enforcement. We will continue to provide updates as we continue to make progress on this key strategic objective.