FOS has written to claims management companies about their use of its services to resolve PPI complaints. It explains its processes and highlights an area of potential abuse by claims management companies. It feels sometimes the companies are raising complaints with FOS before the firm that is the subject of the complaint has issued its final response. Finally, it says it is not appropriate to say firms should consider a general letter about possible past sales as a complaint for the purposes of starting the timeline to FOS referral.