The Financial Regulator has found that around two-thirds of motor insurance companies did not tell policyholders that a settlement had been made following a claim against them.
The regulator said it had recently written to all motor insurance firms with feedback after an inspection of third party personal injury claims.
The inspections were carried out before a new consumer protection code came into force in July last year. The code now requires that the insurance company notify a policyholder in writing when he or she does not benefit from a settlement.
The regulator also found that one in six of agreed settlements took more than 10 business days to be paid. It said the new consumer code would reduce this timeframe.