The mail compromised legal action, but the law firms happened to be bogus. Occasionally Wonga added charges of these emails to subscribers accounts.
The metropolis watchdog, the Financial run power (FCA), said 45,000 clientele was remunerated.
Wonga possesses apologised and explained the approach concluded nearly four years in the past.
The metropolis regulator provides assured the BBC it consists of sent a file for the law enforcement.
The business could be the British s biggest paycheck lender, producing almost four million lending products to at least one million consumers in 2012, popular numbers showcase.
A study unearthed that Wonga sent letters to clientele from bogus law firms called Chainey, D Amato Shannon and Barker and Lowe authentic Recoveries .
The plan was to render subscribers in debt are convinced that their own exceptional debt were died to a law firm, with appropriate motions endangered when the debt was not paid.
They was with this process to maximise collections by piling the pressure on subscribers, the regulator mentioned.
Wonga s misconduct is very serious given that it met with the effect of exacerbating an already difficult circumstances for customers in debt, explained Clive Adamson, manager of direction with the FCA.
The FCA expects agencies to cover specific awareness to reasonable remedy for those who have complications in meeting their own money monthly payments.
The specific situation happened between March 2008 and December 2010, and complex Wonga and various other businesses within their collection.
Because happened until the FCA annexed the management of payday lenders, it is actually unable to fine Wonga. Additionally it claimed there would be no criminal review simply because it wished to developed a compensation scheme immediately and a criminal probe would take time. Influenced buyers will receive about ?50 each.
Rather, Wonga will start talking to visitors in July to offer you settlement, with income probably going to be remunerated in the end of calendar month. That should be paid-in earnings or people should have their outstanding personal debt reduced.
We want to apologise unreservedly to any person suffering from the historical commercial collection agency movements and for any worry ignited as a result, mentioned Tim Weller, interim chief executive of Wonga.
The practise would be unwanted and then we voluntarily discontinued it about four yrs ago.
Anybody who have modified address through the intervening time period should contact Wonga.
Labor MP and campaigner against payday advances Stella Creasy keeps challenged having less violent research.
Exactly why when it comes to those instances where customers of Wonga billed commercial collection agency prices for these emails is that not cops make a difference?, she need on social media optimisation website Twitter.
Richard Lloyd, manager director of customer party Which?, mentioned: really right the FCA has taken a more difficult series on reckless lending it certainly does not come far more irresponsible than this.
It is actually a stunning new low for all the paycheck business that is already dogged by negative exercise and Wonga should have the book hosted at it.
Even more errors
The analysis ended up being begun by FCA s predecessor, the Office of fair-trading (OFT). Wonga mentioned they halted the approach voluntarily after that provided critical information into OFT.
And also, in April this year, Wonga found out that they experienced miscalculated some associates bills.
This lead to 200,000 consumers overpaying the company. Wonga said that most overpaid by below ?5, and a larger amounts underpaid.
People that overpaid can be contacted by Wonga, while the underpaid financial obligation is going to be terminated.
Mr Weller believed the organization will find out from these failure and got reinforcing their internal settings.
The challenges for Wonga come after the company Niall Wass quit after half a year for the career of chief executive. Mr Wass joined up with Wonga in January 2013 as main running policeman – bash artificial attorney techniques ended – and become leader in December.
Before this month, chairman and founder Errol Damelin in addition launched which he had been looking to stop.