Air Canada says economy-class passengers travelling within Canada and to and from the U.S., Caribbean and Mexico will now have to pay $25 to check a bag.

The move matches an announcement made earlier this week by WestJet that it was moving to do the same thing.

The fee only applies to customers on the airline's lowest-fee ticket option, known as Economy Class Tango.

Flyers travelling on Flex, Latitude, Altitude, Prestige, Elite and Super Elite won't be affected. Nor will the travellers flying via the airline's codeshare partners, military personnel or anyone booking wit Air Canada Vacations.

The airline says about 20 per cent of its Canadian customers will be subject to the new fee, and about five per cent of their customers system-wide.

Analysts had been expecting the move, especially after WestJet moved first. It's believed the new fees could bring in between $50 and $75 million a year worth of new revenue for the carrier.