u/nuclear_towel

I have a flight to the US from Pearson tomorrow. My citizenship on Nexus is currently GBR but I want to update it to Canadian as I got my passport last year.

Can I do this pre-flight? My understanding is, go to CBSA early and do that part in Pearson. Then go to regular US customs (not Nexus) and ask them to update it there when I speak to the officer?

Thanks!