Mark D - Just in case EI's computer system doesn't show your onward booking, have details ready of your onward flight so the Check-In agent can through check your bags!
(Often, if you book through ba.com you end up with an Electronic Ticket, although you should have been able to print your itinerary yourself!)
BTW If you're on a One-Way booking, please ensure you have evidence of the right of residency in Canada (either Canadian passport, Residents Permit or a Visa) or evidence of your means of return. Failure to provide this kind of documentation could end in tears!
Hope you have a lovely, festive Christmas over there in Canada......I think your chances of a White one are a little higher than ours!
