Most people need a visa or an Electronic Travel Authorization (eTA) to travel to Canada – not both. Some people may only need their valid passport.
Find out what travel documents you need by visiting the Canadian government visa page.
SPIE recommends that you secure your travel visa before registering for the conference as cancellations after the preregistration cutoff may result in a cancellation fee.
Resources
For tourist visits to Canada of less than 180 days, U.S. citizens do not need visas. Other types of travel generally require visas. Visit the Immigration, Refugees and Citizenship Canada (IRCC) website for current information.
If you have a criminal record, you may be unable to enter Canada. To determine whether you are criminally inadmissible and get information about how to overcome this finding, refer to the IRCC website. Canada Border Services Agency (CBSA) officials determine if you can enter Canada in accordance with Canadian law.
Additional information about travel to Canada can be found here Visit Canada-Entry Requirements
How to request an invitation letter for authors and attendees
IMPORTANT: If you require changes to your invitation letter, go back to your application and add the changes to the section titled "Please list any changes needed to your invitation letter." DO NOT send your personal, identifiable data (i.e. date of birth, passport information, etc.) via email.