Instead of a traditional visa, UK passport holders going to Canada via air should apply for the Canada ETA. The Canadian Electronic Travel Authorization program, completely online, is the easiest and most advantageous way for UK residents to receive authorization to enter Canada.
An endorsed ETA visa waiver is relevant for stays of as long as half a year for travel and business purposes. Similarly, when arriving and exiting by air, UK nationals need an ETA to fly via a Canadian air terminal. For various purposes, for example, work or citizenship or for study, regular Canadian visas are open to British individuals heading to Canada through their nearest Embassy.