Gambling Commission’s Illegal Gambling Index: 2.5% of online players used illegal sites

The Gambling Commission published on 5 November its Illegal Gambling Index, which estimates that 2.5% of people who had gambled online in the past year used an illegal site in the four weeks prior; the report also records that between July and September it referred 7,677,211 URLs to search engines and that 3,019,291 of those URLs were removed. The estimate is based on 3,569 online gamblers surveyed in the Gambling Survey for Great Britain (GSGB) and the index is presented as a baseline, not as an established trend.

Key findings and methodology

The Gambling Commission report, published as Phase 4 of its research with Yonder Consulting on 5 November, does not ask respondents directly whether they intentionally used an illegal site. Instead, the Illegal Gambling Index scores seven self-reported behaviours: using a site known not to be on GamStop, registering because age or identity verification was not required, cancelling a withdrawal, using a VPN to access a site not available in Great Britain, gambling with cryptocurrencies or NFTs, and depositing with a credit card.

The first three indicators are classified as "near certain" because licensed operators must be on GamStop, must verify customers, and, since 2021, must not permit cancellation of withdrawals. The index applies recency weightings: older behaviours count less, and to be counted as a recent user an individual must have a "near certain" indicator or two strong indicators within the previous four weeks.

The data come from four waves of the GSGB between April 2025 and April 2026, all online respondents. Of 3,569 online gamblers (excluding those who only play the National Lottery), 2.5% met the four-week threshold and 1.5% the 12-month threshold; 14.0% showed limited indications and 82.0% none. Among the 14,257 total online respondents, the figures are 0.6%, 0.4%, 4.6% and 94.4% respectively. Only 128 respondents were classified as users of illegal sites, and of that subgroup 58.0% had used a site known not to be on GamStop and 56.6% had cancelled a withdrawal.

"The involvement appears low and stable according to these indicators," said Sue Young, Executive Director for Operations at the Gambling Commission, referring to the index figures.

The Commission excluded a direct question on intentional use from the scoring after finding that many sites named by respondents as "illegal" were, in fact, licensed. The technical report and the updated dashboard accompany the Phase 4 publication.

Enforcement actions and operational outcomes

Between July and September the Gambling Commission referred 7,677,211 URLs to search engines, compared with 147,721 in the previous quarter. In that period 3,019,291 URLs and 1,339 sites were removed from search results. Registrars or hosting providers took down or suspended 7 sites, and operators implemented 25 geo-blocks. Cease-and-desist letters to illegal operators rose to 546 from 217, and 4 criminal investigations were opened in the quarter. For more on regulatory enforcement, see [enforcement and regulatory action](/regulation).

In the 5 November CEO Briefing appearance, interim chief executive Sarah Gardner said that between April and September 7,824,932 URLs were referred to search engines, compared with 397,527 in the whole of 2025/26. Gardner linked the scale of the operation to a government commitment of £26 million over three years, a funding line she had outlined to other regulators in October.

The Commission qualifies that the increase in referred URLs reflects greater granularity, not necessarily an equivalent increase in operator numbers: the number of URLs per referred site rose from about 400 in the first quarter to about 4,200 in the second, and the removal rate was 39% of referrals in the quarter versus 67% in 2025/26 as a whole. No disruption to payment provisions was recorded during the quarter.

External reactions and market estimates

Gambling Compliance International (GCI) emphasised that the share of people using illegal sites is not the same as the share of revenue those sites generate. Ismail Vali, chair of GCI, said: "A relatively small audience, particularly concentrated in vulnerable, repeat or high-value gambling behaviours, can generate substantial criminal revenues." GCI, in research for the Campaign for Fairer Gambling, estimated that illegal online GGR in Great Britain was approximately £780 million in 2025, nearly 9% of the online market, as reported by iGB.

GCI also noted that the adult survey does not include minors and that self-excluded players require specific analysis.

Limitations, dashboard and next steps

The Commission describes the index as a baseline with one year of data and cautions that any judgment about stability should come from the updated data dashboard. On the dashboard the Commission counted 586 accessible sites in September 2026, compared with 439 in May 2024; estimated traffic to those sites, modelled from Similarweb and scaled for VPN use, fell by around one third between those dates. The Commission acknowledges that more supply and less use is plausible, but notes that this point rests on modelled traffic.

The Commission plans to add persona questions to the GSGB in 2027 to show how concentrated the cohort of users is. The index already provides a repeatable measure and, together with increased resources and the mass referral of URLs, forms part of a combined measurement-and-action strategy.

"The focus may evolve with respect to some of these numbers," said Sarah Gardner during the CEO Briefing, referring to how to interpret referral metrics.