A release from the insurance corporation says letters will be sent to all customers who either overpaid or underpaid for optional insurance coverage.
"We sincerely apologize for any inconvenience this has caused our valued customers," said a news release issued by spokesperson Adam Grossman.
Drivers who overpaid will be reimbursed, say ICBC, with the average cheque amounting to about $18 for each year of the error.
Drivers who underpaid will not have to repay any cash. ICBC says the issue has cost it more than $100 million in either lost revenue or reimbursements.
ICBC says the wrong premiums were charged because the wrong vehicle description was applied, but new software will prevent the issue in future.
"This is a very complex issue and ICBC is committed to ensuring there is accurate information on vehicle descriptions for all customers prior to launching a new computer system for its insurance business," said the news release.
The new technology automatically identifies the vehicle's description using the vehicle identification number (VIN) provided by the vehicle’s manufacturer.
ICBC urges anyone with additional information to provide or questions about their letter to call ICBC at 604-904-8211 in the Lower Mainland or 1-866-506-0030 toll free within B.C.