All travellers that are travelling to Canada by plane and don't possess a Canadian or US passport, need to apply for an eTA Canada before their flight. This is a mandatory travel permit which you need to possess before you are allowed to check-in your luggage or board the plane to Canada.
can be compared to an electronic visa for Canada. It costs £19,95 per traveller (business or tourist) and can be applied for online.
Applications submitted online are granted within 72 hours and confirmed by e-mail.