Given the longer processing times at U.S. customs and immigration check points, it is recommended that travellers flying to the United States allocate additional time to proceed through most Canadian airports offering U.S. pre-clearance. If you are attending a conference or convention, it is also advised to have your paperwork readily available, such as an agenda or registration confirmation to accelerate your processing.
Should you frequently fly into the US, the NEXUS program allows low-risk pre-approved travellers to use designated border crossings without being subject to regular questioning by customs and immigration officers, significantly speeding up the process.
For those travelling without pre-approval, we recommend you allow as much as 3 hours for check-in and customs clearance.
For additional information, you may also contact preclearance locations.