Originally Posted by mnbp

Locations that record iris scans are listed here (with hours of operation). No appointment is necessary (or possible) for adding an iris scan to an existing Nexus membership:
https://www.cbsa-asfc.gc.ca/prog/nex...ation-eng.html

Please note that CBSA is retiring iris scans as the "fingerprint" for Nexus in favor of facial recognition (photograph). At some airports, iris scan machines are no longer present:
https://www.cbsa-asfc.gc.ca/prog/nexus/kiosk-eng.html
https://www.cbsa-asfc.gc.ca/prog/nexus/rec-eng.html