Business Editor The Central Bank has found that a majority of insurers are using a controversial practice known as differential pricing in calculating how much customers premiums should be. The regulator has established that these techniques are leading to customers with similar risk and cost of service profiles paying different premiums for reasons other than risk and cost of service. The bank's interim report on the practice of differential pricing also found that dual pricing, where new and renewing customers are charged different premiums for reasons other than risk and cost of service, is evident across the private car and home insurance markets.