Will my friends have to pay a full air fare for their child?

Simon Calder answers your questions on flight cancellations, refunds for late trains, and the most interesting London bus routes

Any chance of a sit-down? Passengers queue at Gatwick airport (Simon Calder)

Q Here’s an interesting one for you, and I’m not sure of the answer. A couple of my acquaintances booked a flight for themselves and their under-two infant. The airline cancelled the flight, so they now have to move to a date when their child will be two years old.

Can the airline charge them more for a normal fare rather than the infant fare? Or must the original contract be honoured?

Jamie B