The Canadian Office and Professional Employees Union, local 378, says the job action affects about one-third of ICBC's workforce.
Offices and outlets in Metro Vancouver are primarily affected by Wednesday's strike, the third to be staged by COPE members seeking an improved wage offer from the corporation.
Five of 16 driver licensing offices in the Lower Mainland have been closed because of the job action.
COPE local president David Black says members are frustrated by the lack of progress in reaching a deal.
He says the union believes a better wage offer is realistic because ICBC has increased payments to executives and business partners and also submits $1.2 billion to the provincial government.
Note to readers: This is a corrected story. An earlier version said Kamloops and Victoria drivers centres were closed. In fact, five Lower Mainland licensing offices are closed.