The ‘lead generation’, Brighton-based Prodial Ltd, was behind millions of automated calls which played recorded messages relating to PPI claims.
Operating out of a residential property and hiding its true identity, making it harder for people to report the calls, the firm still generated more than 1,000 complaints.
One in seven people targeted by Prodial said they were left feeling helpless that they could do nothing to stop the calls which were extremely intrusive and at all times of day and night.
Companies can use internet phone lines to cheaply make huge numbers of recorded marketing calls - but the law states that firms can only make calls to people who have consented to being contacted in this way.
However, Prodial had no such consent; and evidence from the investigation showed personal details from the calls was sold on to claims-management companies. Records indicated that, despite a marketing campaign which could have produced a turnover of nearly £1 million, the company has been placed into voluntary liquidation by one of its directors.
Information Commissioner Christopher Graham said: ‘This is one of the worst cases of cold calling we have ever come across. The volume of calls made in just a few months was staggering.
The ICO’s enforcement team is currently working with the liquidators to recover the fine.
Which? executive director Richard Lloyd said: “Millions of people are bombarded with nuisance calls, so it’s good to see the ICO issuing ever larger fines to tackle this everyday menace.
He added: “We now need to see the government introduce tougher penalties for senior executives of companies making unlawful calls, including ensuring that board directors are held personally accountable.”