The amount wagered with unlicensed gambling operators in the UK has reached £16.6bn ($22.6bn), more than tripling since 2019 and doubling in just the past two years, according to new independent analysis by H2 Gambling Capital (H2GC).
The data shows offshore betting activity growing from approximately £5bn in 2019 to £16.6bn in 2025, with both stakes and operator profits doubling between 2023 and 2025 alone.
Over the same period, the share of gambling taking place on regulated sites has fallen from 97% to 92%, meaning a growing proportion of bets are now placed outside the protections of the licensed market.
H2GC attributes the rise of the black market to a combination of factors, including increased regulatory pressure, higher taxation and the growing online visibility of illegal operators.
Separate research by WARC indicates that illegal operators now account for almost half of all UK gambling advertising spend – a share projected to become a majority within two years.
The Betting and Gaming Council (BGC) has raised concerns that further tightening of rules – including proposed financial risk assessments – could accelerate this trend by making regulated operators less competitive.
The organisation argues that any friction introduced into the regulated market risks redirecting customers toward illegal sites that offer no consumer protections, pay no UK tax and operate entirely outside domestic rules.
BGC has also been taking steps to tackle the issue directly with consumers. The organisation recently launched an interactive quiz, 'Spot The Black Market', designed to help members of the public identify illegal casino operators and understand the risks they pose.
The free-to-play game walks players through scenarios and statistics covering how black market sites operate, what player protections they lack and how to verify whether a site is legitimately licensed via the Gambling Commission register.
Illegal gambling operators are estimated to cost the UK up to £67m in lost excise duty each year – equivalent to the salaries of around 1,750 nurses