On the Processing facilities to international destinations (with added business days) by service page, use the table corresponding to the service you’re using (for example, Xpresspost™ – International) to determine to which of the 3 processing facilities (Montreal, Toronto, Vancouver) the shipment will be sent based on your originating Forward Sortation Area (FSA).
Remember the number of extra business days so you can add it to the delivery standard.
If your FSA 1 is between P0V and T9X, X0B and X0G, or Y0A and Y0B you must use the instructions in the Delivery standards by service - Parcels (Canada) page to find the domestic Xpresspost standard between your FSA and the forward processing facility identified.