Split Itineraries: Baggage Risks
 

I'm traveling today on 2 separate tickets: (1) YQY-YHZ-YYZ (WestJet), (2) YYZ-IAH (Air Canada). I have a tight connection in YHZ. If my bags don't make the flight to YYZ... can I board my flight to IAH without them? Are there any services available to get my luggage sent to me if they have not been checked through to my final destination?

How tight is this connection? If you mis the YHZ-YYZ flight and get put on a later one, will you still make YYZ-IAH? If not, you should note that the return IAH-YYZ flight will be cancelled as you will be deemed no-show for the first segment.

In terms of your first question, you need to check whether WestJet and AC interline. If they do, you should be able to check your luggage all the way to IAH. If they don't you'll have to pick it up in YYZ and check in or bag drop for the IAH flight. If you don't pick it up personally and the bag is only tagged to YYZ, it'll stay there and not make its way to IAH.

Can you avoid checking bags? Even if the carriers interline, some refuse to check bags through when there are separate tickets.

Interlining is not the issue. All that means is that there is an agreement between the carriers that they may check bags through. On separate tickets, many carriers choose not to and a few agents will nonetheless do it.

Bear in mind that as you are on separate tickets, if you no show for your AC flight, that entire ticket will be cancelled and will retain any value which the fare conditions provide for. Thus, make sure that you do not have tight connections (at YHZ) or a tight transfer time (at YYZ), as there is financial risk here.

Correct, that's why I said 'may'. I've been able to through-check bags to the final destination of a second ticket. That was on a UA/AC combination a few years ago. Personally I would do as you suggested and leave a great deal more time for both connection points.