Air Canada travellers need to make sure their carry-ons are the right size or they will pay more to fly.

Starting Monday in Toronto, Air Canada will begin enforcing the size and weight limits for carry-ons. If they exceed the limits, passengers will be charged $25, and the baggage will have to be checked in.

Staff will tag carry-on baggage that falls within the proper dimensions.

Air Canada said the new protocol will be rolled out to other Canadian airports, such as Winnipeg James Armstrong Richardson International Airport, next month.

Passengers are advised to weigh and measure their luggage before checking in at the gate.