From the Government of BC

You must register to collect PST if you are located in B.C. and you sell or lease taxable goods, or provide software or taxable services in the ordinary course of your business in B.C. You may also need to register if you’re located outside B.C.

For detailed information about how to register and who must register to collect PST, see Registering to Collect PST (Bulletin PST 001) (PDF, 376KB).