Payday loan firm Wonga has suffered a data breach Attack.Databreach affecting up to 245,000 customers in the U.K. A further 25,000 customers in Poland may also be affected , according to the BBC . It says it does not believe customers ’ Wonga account passwords were compromised Attack.Databreach but suggests concerned users change their password anyway . Wonga is warning affected customers to be “ extra vigilant ” and to alert their bank of potential risk — though it says it will also be contacting financial institutions about the breach . We ’ ve reached out to Wonga with questions and will update this story with any response . Update : In a statement a spokesperson for the company told us : “ Wonga is urgently investigating illegal and unauthorised access Attack.Databreach to the personal data of some of its customers in the UK and Poland . We are working closely with authorities and we are in the process of informing affected customers . According to The Guardian , the company became aware of a problem last week but only realized on Friday that data could be accessed Attack.Databreach externally , and only started contacting affected customers on Saturday . The U.K. ’ s data protection regulator , the ICO , has apparently been informed of the breach — although it ’ s unclear when . An ICO spokesperson did not respond to the question , providing this statement instead : “ All organisations have a responsibility to keep customers ’ personal information secure . Where we find this has not happened , we can investigate and may take enforcement action ” . Back in 2014 the company had to write down $ 340 million in unpaid loans , following an investigation by the U.K. ’ s Competition and Markets Authority over its lending practices . It was also fined by the regulator for sending Attack.Phishing fake lawyers ’ letters to customers in arrears . Although Wonga attracted substantial tech investment for a real-time automated decision-making platform for affordability checks , it ended up having to write off the loans of 330,000 customers , and waive the interest and fees for a further 45,000 — raising questions about the efficacy of its algorithms . Tightened criteria on short-term loans by the U.K. financial regulator ultimately shrunk the size of Wonga ’ s business , which saw losses double in 2015 — to £80.2 million .