When you apply for an Electronic Travel Authorization (eTA) for Canada, you are not automatically assigned a Unique Client Identifier (UCI) number. The UCI is typically assigned to individuals who have previously interacted with Canadian immigration services, such as applying for a visa, study or work permit.
If you are applying for an eTA for the first time and have never interacted with Canadian immigration before, you will not have a UCI. In this case, if the application form asks for a UCI, you should write “Not Applicable” or “N/A” in the space provided. If you are applying online and the form does not allow you to type “N/A,” you should leave the space blank.
The UCI is an eight or ten-digit number that looks like this: 0000-0000 or 00-0000-0000 and is used to identify your file in the Canadian immigration system for any future applications you submit to Immigration, Refugees and Citizenship Canada (IRCC).