Originally Posted by
CarNut
I am going to book a Latitude fare so that I can do my US Nexus interview. Is there a cut off time for cancelling before the flight departure time?
CarNut
Your question is about Latitude cancellation cut-off, which I may need to do soon for a different reason.
The International Tariff Rule 70 says must check-in within 60 minutes except for YYZ which is 90 minutes, and then refers to you Refund for process.
To enter Preclearance you will need to check-in otherwise you will not be permitted entry (boarding pass will be scanned to enter CATSA screening), but you can always cancel your check-in, presumably before these mandatory cut-off times to get refund.
And regarding whether you can or cannot enter Preclearance for your stated purpose, a substantial discussion appears here, if I understand the Bulletin Rules correctly .
Recent/Current YYZ-USA Preclearance Experiences
good luck