ATPDR Section 25(1), in plain language
Section 25(1) of the Accessible Transportation for Persons with Disabilities Regulations is the rule that lets your service dog travel with you on federally regulated carriers in Canada.

Photo: Timur Shakerzianov / Unsplash
What the section says
In plain terms, a carrier must accept a service dog when you provide, on request, documentation confirming the dog was individually trained by an organization or person specializing in service dog training to perform tasks that assist with your disability.
The duty sits with the carrier. You are not required to hold a government card or registration, because no such national registry exists.
Who it applies to
ATPDR binds carriers in the national transportation network: air, rail, marine, and interprovincial bus. It came into force in 2020 under the Canada Transportation Act.
What it means for you
Your dog travels in the passenger space with you, not as cargo, and a carrier cannot charge a pet fee. A carrier may ask for advance notice so it can plan space, which is a logistics step, not permission to travel.