The head of a scheme designed to help problem gamblers says she is "deeply concerned" after an investigation found people were able to cheat the system.
More than 50,000 people have signed up to GamStop, which was launched in April 2018 to allow addicts to ban themselves from online betting platforms.
The BBC found a gambler who had self-referred could still place bets online by simply changing their user details.
GamStop's Fiona Palmer admitted the service was not working well enough.
The Gambling Commission said it was looking to bring in tougher ID checks.
What is GamStop?
GamStop is a free, independent self-exclusion scheme for people with online gambling problems.
Gamblers register their details and choose how long they want to be banned for. They should then not be able to logon to gambling websites.
However, by changing a few small details - including misspelling a surname - BBC Radio 5 live Investigates discovered it was still very easy to open a new account and continue gambling, even while banned.
Adam Bradford, from Sheffield, only discovered his father David's online gambling problem in 2014, when David was jailed for two years for fraud.
He had stolen £50,000 from a former employer to fund his all-consuming habit. In total, Mr Bradford lost more than £100,000 gambling online.
His son now campaigns to raise awareness around the risks of online gambling.
As part of the investigation, he registered himself with GamStop. However, a few days later he showed 5 live Investigates how he was able to open a new online betting account by simply using a different email address and changing a letter in his name.
He was even offered £50 in free bets.
Adam Bradford said other people had told him how easy it was to bypass the exclusion system.
"I think it's scandalous - it means the hundreds of thousands of betting addicts across the country are not being protected. The industry is putting up what I think is a facade. It doesn't work," he added.
When presented with the findings, the chief executive of GamStop, Ms Palmer said: "We are taking on board the feedback and we are looking to improve the scheme".
The Gambling Commission, which regulates the industry, has said it will soon announce the results of a consultation on using ID verification, which would prevent customers gambling using incorrect details on online gambling sites.
BBC Radio 5 live Investigates also found that the self-exclusion scheme for High Street bookmakers is seriously flawed.
Last year, a 5 live producer excluded himself from 21 betting shops in Grimsby, Lincolnshire, using the Multi-Operator Self Exclusion Scheme (MOSES).
However, he was still able to bet in 19 of them.
The operators of the scheme, the Senet Group, said lessons would be learned.
Twelve months later, a different BBC producer banned himself from 20 of the same shops in the town and was allowed to place bets in 15 of them.
The Association of British Bookmakers (ABB) said it was "disappointed" with the findings.
However, the trade association added that it was encouraged by the results of a survey of genuine participants of the scheme.
The ABB said an independent survey carried out by charity GambleAware found that "83% said that it had been effective in reducing or stopping their gambling activity and 71% said they have not attempted to use their nominated betting shops since signing up".
The Senet Group, which uses funding from bookmakers to run the scheme, said "the results of this investigation are disappointing" but insisted MOSES is an "important first step for people who genuinely want to reduce their gambling".
However, shadow culture secretary Tom Watson said the investigation demonstrated the two schemes "aren't fit for purpose".
He promised to take the BBC's findings to the government.
Labour MP Carolyn Harris, who chairs a cross-party group of MPs on gambling-related harm added: "Any system which is easily manipulated like this is not worth it - they have to be robust enough to withstand deliberate attempts to get around them."
You can hear more on 5 live Investigates at 11:00 GMT on Sunday 13 January on BBC Radio 5 Live and BBC Sounds.