TLDR
- Britain’s illegal gambling market has reached £16.6bn in stakes, more than tripling since 2019 according to H2 Gambling Capital research shared by the Betting and Gaming Council.
- Offshore betting stakes doubled between 2023 and 2025, with the steepest growth in the most recent two-year period.
- The legal gambling market share has fallen from 97% in 2019 to 92% in 2025 as more bettors move to unlicensed sites.
- Illegal operators now account for nearly half of all UK gambling ad spend and are expected to hold the majority within two years.
- The BGC warns that higher taxes, tighter rules, and proposed financial risk checks are pushing customers toward unregulated platforms that offer no consumer protections.
Britain’s illegal gambling market has ballooned to £16.6 billion in stakes, according to new research from H2 Gambling Capital. The figures were shared by the Betting and Gaming Council, the trade body representing the UK’s licensed gambling industry.
The black market has more than tripled since 2019. It has doubled in just the last two years, with the sharpest growth occurring between 2023 and 2025.
At the same time, the share of gambling taking place on regulated sites has dropped. In 2019, legal operators handled 97% of all gambling activity. That figure now sits at 92%.
Offshore Operators Gain Ground
Offshore betting stakes rose from roughly £5 billion in 2019 to £16.6 billion in 2025. Operator profits from those illegal sites also doubled during the 2023 to 2025 period.
Separate research from WARC found that illegal operators now account for nearly half of all gambling advertising spend in the UK. That share is expected to become the majority within the next two years.
The unlicensed sites pay no UK tax. They also offer none of the responsible gambling protections that licensed firms are required to provide.
The growth has been linked to a combination of higher taxes on the regulated industry, tighter operating rules, and new proposals for financial risk checks on customers.
Those measures, while aimed at protecting consumers, have made the legal market less competitive. Illegal operators have stepped into that gap.
They have become more visible online and more aggressive in how they target UK customers. Their marketing tactics have grown more sophisticated in recent years.
Grainne Hurst, Chief Executive of the BGC, said the trend should worry anyone who cares about consumer protection. She described a harmful black market that is scaling up at pace.
Hurst warned that customers will not stop gambling if the regulated sector becomes harder to use. Instead, they will move to unsafe sites with no protections in place.
BGC Calls for Balance on Regulation
The BGC has taken aim at proposed financial risk assessments in particular. Hurst said these checks must be “genuinely frictionless” or not introduced at all.
Anything short of that, she argued, would push more customers out of the regulated market and into the hands of offshore operators.
The council stressed that efforts to reduce gambling harm need to be balanced carefully. Overly strict rules risk strengthening the very black market they are trying to fight.
The regulated gambling industry currently raises £4 billion in tax revenue each year for the UK government. The BGC has warned that revenue is at risk if the legal market continues to shrink.
Unlicensed operators contribute nothing to that tax base. They also fall outside the reach of UK regulators.
The debate comes at a time when policymakers are weighing new gambling reforms. The government has been considering a range of measures following its gambling white paper.
The H2 Gambling Capital data adds fresh urgency to that discussion. The figures suggest the black market is growing faster than many had expected.
As of 2025, illegal gambling stakes in the UK stand at £16.6 billion, with the BGC warning that without careful policy, that number will continue to climb.
