Online betting in Britain has about 20 million active punters, who wager on sports from football and tennis to golf and horse and greyhound-racing, as well as card games like poker. They lost £3.6 billion (S$6.1 billion) last year.
It is illegal for anyone under 18 years old to gamble, and bets must be placed with a licensed operator.
The growing popularity of online betting has seen the country's gaming regulator give out a total of 749 licences as of March this year.
The Gambling Commission was set up after gambling laws were liberalised in 2005. It has the power to prosecute anyone who runs foul of the Gambling Act, which ensures there is no link between gambling and crime or disorder, that gambling is conducted fairly and openly, and children and vulnerable adults are protected from harm or exploitation.
However, healthcare professionals and charities are worried about the rising number of gambling addicts. There are about 500,000 in Britain.
GamCare, a charity that provides counselling and a helpline to gamblers, said the number of people it was treating rose to 5,500 last year, nearly 40 per cent above the previous year's figure. Nearly half of those who seek help say they are online punters.
To combat the problem, the Gambling Commission introduced new rules that allowed online customers to take between 24 hours and six months off from betting while keeping their online accounts open. They can also deactivate their accounts by simply ticking a box, rather than calling the betting operator, which was the case previously.
In April, a 23-year-old accountant jumped to his death from the ninth floor of an office building in London, after debts piled up from his addiction to online gambling.
Mr Josh Jones told his parents before his death that he could not resist the lure of PokerStars, the world's largest online poker site. He owed £30,000 to banks, loan companies, family and friends.
To control his addiction, he had imposed a six-month self-exclusion from the site. But when PokerStars sent him an automated e-mail to rejoin the site after the six months were up, he started gambling again.