The Central Bank has ordered an insurance company to repay €2m to its customers.
The bank also handed out a record fine of €3.35m to the Combined Insurance Company of Europe after it breached regulations.
The fine is the largest the Central Bank has handed out to a financial services firm.
The bank reprimanded Combined Insurance Company of Europe for breaching guidelines aimed at protecting consumers, as well as other regulations covering the selling of insurance.
The UK's regulator has also fined its UK business £2.8m.
The breaches of the rules took place between August 2006 and April 2011. More than €560,000 has already been refunded to customers.
The company's policies were sold by a network of tied agents. The Central Bank found that some of these acted "dishonestly, unfairly and unprofessionally".
It said agents wrongly obtained customers' bank account details and used them to set up policies in other people's names.
In other cases, customers' bank account details were used to set up additional policies for these customers without their permission.
The Central Bank blamed the company's system of paying the agents, which was commission-only and based on sales targets, created a "high pressure" sales environment.
For more information customers of Combined Insurance can contact a helpline at 01-4402781 or email csd@ie.combined.com
