Rory Boland, travel editor at consumer publication Which?, says overall cancellations will be a very small proportion of the millions of flights in and out of the UK, and the changes will be targeted on routes where there are multiple flights a day so that passengers can be rebooked on to an earlier or later flight.
But some passengers may find they are bumped on to a next-day flight, disrupting their holiday plans.
Airlines cannot up the price once you have bought your ticket.
Low-cost Spanish regional airline Volotea has come under fire for saying it will add a surcharge to tickets it has already sold and is being challenged by local consumer rights groups.
An airline or tour operator could only raise the price post-sale if they had a specific caveat written into the terms and conditions, says independent consumer commentator Jane Hawkes.
Airlines are more likely to raise future prices, including for hold baggage or other extras, she says.
However, when it comes to package holidays, tour operators can add up to 8% to the cost of your deal after you’ve booked, based on a “significant rise in fuel costs”, says Boland. But Which? found most operators were promising not to add surcharges this year.