The Gambling Commission said several research methods only offered limited insight into illegal online gambling in their current forms.
Great Britain’s Gambling Commission has said it remains uncertain as to how much players are spending with illegal operators, with current measurement and monitoring methods offering limited insight into the issue.
The regulator mapped out its concerns in the fourth and final chapter of its research into illegal online gambling. The report considered the challenges of estimating the size of the market and the commission’s recommendations for further progress.
The report considered three approaches to estimating the scale of illegal online gambling in Britain, including dwell time approach, which converts data on engagement and ‘time-spent-on-site’ into expenditure estimates.
The second method is the channelisation approach, based on comparing data on legal and illegal ‘channels’ of engagement with gambling. Finally, the survey-based approach involves players responding to pre-set questions.
Of these three, the Gambling Commission only pursued the dwell time and channelisation methodologies in its four-part report. It said underlying data from surveys was unreliable as consumers’ recall of past expenditure in gambling surveys is “generally poor”.
However, the regulator said neither of the other two approaches presented enough data to allow it to form an accurate view of the illegal market, saying more work is required to make progress.
Minimal findings from dwell time approach
From the data drawn from dwell time and channelisation approaches, the regulator was able to present some findings.
Referencing dwell time results, it looked at the activity of 117 players gambling with illegal websites. Sports betting was the most popular activity with an average of 34% of players taking part, ahead of bingo on 14% and slot and instant win, both with 13%.
However, the primary limitation here was the size of the sample and it not being fully representative.
Also within this section was ‘Patterns of Play’ research on expenditure per minute in the legal market. This showed casino as the main vertical, with £1.12 gross gambling yield (GGY) per minute, ahead of slots on £0.32. However, with the data coming from 2018-19, it was seen as outdated compared to the current market.
The final piece of research looked at online slots GGY per minute between 2020 and 2025. This remained relatively steady throughout, with the most recent rate being £0.24 in March this year.
“Dwell time approach allows us to attempt to convert objective estimates of engagement data using known data from legal market,” the regulator said. “This requires several assumptions to be made – each introducing additional uncertainty to these estimates. Further work on these actions is required before we will reach a position where reliable estimates can be published.”
Channelisation rate far from clear for Gambling Commission
Turning to the channelisation approach, the regulator said while there is potential with this method, more work is needed to verify the accuracy of estimates of web traffic and app use in the legal market to allow reliable channelisation rates to be estimated.
It created a list of all websites associated with operators licensed by the commission and can use digital data company SimilarWeb for estimates of numbers of visits and duration. However, there are some limitations, including that it does not usually observe app versions of illegal websites
“Given the likely strong degree of app-based spend in the legal market, we also need to obtain web traffic data for both apps-based and website-based engagement with legal sites,” it said. “SimilarWeb provides estimates of both. Ideally, we would benefit from operators’ insights to help us verify the accuracy of these estimates.”
Then there were limitations on GGY data and using this to estimate activity within the illegal market. This, it said, related to the margins of error associated with each estimate. It gave the example of statistics covering the period April 2023 to March 2024, which showed total online GGY of £6.9 billion. If channelisation rate estimate was out by just 0.5%, this would be a difference of £34.5 million in the associated estimate of GGY.
What does the Commission plan to do?
In its conclusion, the regulator said while each method has limitations, there are options to open-up a pathway to allow a “robust estimate” of illegal online gambling in Britain.
For the dwell time approach, these options include using data from consumers who have used illegal websites to understand how they differ from legal operators. It will also consider using data from licensed operators to shed light on betting spend and engagement, as well as updating the Pattern of Play report with fresh data.
The Commission also said it could look at trends in VPN downloads to see how many players could be accessing illegal, overseas sites. In relation to this is a potential focus on key search terms for unlicensed sites and the volume of these within search engines.
“Developing this estimate is a worthwhile exercise,” the regulator said. “We recognise that several third parties have published estimates.
“While we welcome the focus on this issue, and recognise the concern stakeholders have about illegal gambling, we urge caution over use of estimates where the methodologies are not clear and levels of uncertainty are not set out.”
Ongoing commitment by the Gambling Commission
The report’s conclusion echoed comments from John Pierce, director of enforcement and intelligence at the regulator. In a recent blog, he set out the commission’s commitment to improving its approach to researching and tackling illegal gambling in Britain.
Among these efforts, Pierce said, are strengthening intelligence capabilities and forging new partnerships across technological and financial sectors and with international regulators. He also noted investment in organisational resilience such as developing new tools, equipping its teams with the right skills and targeted research and data.
“Illegal gambling is not a static threat,” Pierce said. “It is adaptive, opportunistic and increasingly embedded in digital ecosystems on the international stage. Through targeted disruption, strategic partnerships and continued investment in capability, we are building a resilient and effective framework to protect consumers and uphold the integrity of the regulated sector.
“We are making progress; and we are committed to going further.”