s it steps up its investigation of the £4.5 billion sector, the CMA is acting because it believes people aren't getting the deal they expect from sign-up promotions, and operators are unfairly holding on to people's money.
This follows a joint program of work between the Gambling Commission and the CMA to tackle a shared concern about whether people are being treated fairly by online gambling operators.
Sign-up promotions are designed to attract players onto casino-like gaming websites by offering bonus cash when they put in their own money. However, the CMA is concerned that people often don't get the deal they are expecting, as the promotions come with an array of terms and conditions that are often confusing and unclear and, in some cases, may be unfair.
Customers might have to play hundreds of times before they are allowed to withdraw any money, so they don't have the choice to quit while they're ahead and walk away with their winnings when they want to.
Even when players haven't signed up for a promotion, there are concerns that some operators are stopping customers taking money out of their accounts. The CMA has been told by customers that some firms have minimum withdrawal amounts far bigger than the original deposit, or place hurdles in the way of them withdrawing their money.
Nisha Arora, CMA Senior Director for Consumer Enforcement, said, "We know online gambling is always going to be risky, but firms must also play fair. People should get the deal they're expecting if they sign up to a promotion and be able to walk away with their money when they want to.
"Sadly, we have heard this isn't always the case. New customers are being enticed by tempting promotions, only to find the dice are loaded against them. And players can find a whole host of hurdles in their way when they want to withdraw their money.
"That's why we are today launching enforcement action where we think the law has been broken. We are also asking people who have had difficulties withdrawing their money when they've gambled online to tell us about it and help probe this issue even further."
Gambling Commission Chief Executive, Sarah Harrison, added, "Gambling operators must treat customers fairly, but some have been relying on terms that are unclear with too many strings attached.
"Whilst the CMA takes enforcement action on how consumer legislation is followed, the gambling industry should be under no illusion that if they don't comply with consumer law, we will see this as a breach of their operating licence and take decisive action.
"The CMA opened an investigation into the gambling sector's compliance with consumer protection law towards the end of last year after hearing about a range of concerns that suggested some operators were not treating their customers fairly. As well as hearing from around 800 unhappy customers, it has also demanded companies answer questions about how they operate, and closely examined the play on a range of websites."
Having identified a number of operators engaging in practices likely to be breaking consumer law, the CMA is now taking enforcement action and has a range of powers at its disposal to bring any illegal activities to an end.
This investigation is part of a joint program of work with the Gambling Commission to tackle issues around fairness and transparency in the gambling industry. As well as the enforcement cases, the investigation may lead to further action, from the CMA or the Gambling Commission, to improve practices across the online gambling sector.