A third airline has been awarded a licence to fly between Guernsey and Jersey, but ticket sales have been restricted by Guernsey's Transport Board. Flybe will now operate in direct competition with Rockhopper and the Guernsey States-owned airline Aurigny.
But bookings can only be made in Guernsey less than 24 hours before people want to fly.
The restrictions were imposed by the Transport Board to ensure that the existing operators were unaffected.
People living elsewhere in the Channel Islands can book as far ahead as they like.
Flybe manager Ian Taylor said: "The restrictions on sales of our tickets are very frustrating for the company, as we cannot offer passengers the same choice of service as other airlines."