If I am flying on an itinerary with a stop-over (For example, YVR-YYC(stop)-YYZ-YVR) and I have an extra bag to check, does AC only collect excess charges once, or each time that I have to check-in?

I would assume that they would collect in YVR on the outbound and YYZ on the inbound, but do they also collect in YYC? Thanks

[edited for clarity]

[This message has been edited by makin'miles (edited 04-04-2001).]