Meeting all the points mentioned below would be a great prevention of the penalties while flight cancelation.

• According to Westjet Cancellation Policy, 24 hours of booking is the risk free period when one can cancel their flight for free.
• A 24-hours cancellation policy is applicable for the customers who bought the air tickets a week earlier than the scheduled departure. 
• WestJet Airlines deducts from the booking value when the canceled flight is refundable and it's been canceled after 24 hours of booking.
• Further, if the customers cancel their non-refundable fare after 24 hours of booking they need to pay an extra amount as the penalty.

How Much Does WestJet Airlines Charge for the Flight Cancellation?

As per WestJet Airlines, one can change their bookings or cancel their air tickets for a fee up to seventy two (72) hours earlier than the flight departure. One is liable to a fee of up to $185.00 CAD/US (plus tax) per person per trip and the remaining amount will be reimbursed as a credit value with WestJet valid for a year. To know more about it read the full Blog.