The 9-digit Property Identification Number (or PID) can be found on the Property Assessment Notice from the taxation authority. The PID is also included on the yearly assessment notice from the city or taxation authority.
If you do not have the assessment notice, often the city may provide the PID to the homeowner over the telephone.
Should these options not be available, BC Assessment has a service on their website (www.bcassessment.ca) called e-value BC where you can get detailed assessment information. Or you can do a BC Assessment search through BC OnLine which will show the PID.