William Hill customers have been allowed to spend thousands of pounds in just a few minutes with no restrictions after "widespread and alarming" failures at the company were exposed.
The gambling regulator handed their parent company a record-breaking fine of £19.2 million after the serious lapses in customer safety across three businesses came to light - and warned they had seriously considered suspending the bookmakers' licence during their investigation.
A report from the Gambling Commission discovered new customers were able to spend large amounts of money quickly without any checks taking place, with one racking up £23,000 in only 20 minutes.
One William Hill customer lost £54,252 in four weeks without the operator seeking any evidence of income or carrying out adequate checks, and another did not receive a telephone call from the operator until losses reached £45,800.
The failure to apply a 24-hour delay between receiving a request for increased credit and granting it additionally led to a customer being allowed to immediately place a £100,000 bet when his credit limit had been set at £70,000.
Because of lapses in protections supposed to help gamblers impose their own spending limits, 331 customers were able to gamble with William Hill Group (International) despite having self-excluded from Mr Green, which is owned by the group.
Failures to implement anti-money laundering measures were also highlighted in the investigation.
Andrew Rhodes, the Gambling Commission's chief executive, said the regulator chose not to suspend the bookies' licence after they worked "swiftly" to implement new measures following their investigation.
He said: "When we launched this investigation the failings we uncovered were so widespread and alarming serious consideration was given to licence suspension"
"However, because the operator immediately recognised their failings and worked with us to swiftly implement improvements, we instead opted for the largest enforcement payment in our history."
All £19.2 million will be directed towards socially responsible purposes as part of their settlement, the Commission said.
New licence conditions will also be given to the William Hill Group to ensure a business board member oversees an improvement plan, while a third-party audit will also assess its anti-money laundering and safer gambling policies, procedures and controls.
