The International Civil Aviation Organization (ICAO) defines a low-cost carrier by its relatively low cost base and low fares, and says it can be an independent airline, part of a larger airline group or a former charter airline. The usual model relies on one or two aircraft types, aircraft that fly many hours a day, a single cabin and low base fares with paid ancillaries such as bags and seats.

How agents sell low-cost flights

Low-cost airlines decide how their flights may be sold, and their approaches differ:

• some sell through approved GDS and aggregator channels, with agreements for travel trade partners

• some name approved online partners, and their website terms say only their own site is authorised to sell their flights and ban commercial use

• holiday companies linked to some airlines sell packages that include their flights through travel agents

ATOL and packages

• Combining a low-cost flight with a hotel at one price creates a flight-inclusive package that needs ATOL cover. The flight-only exemptions never apply to packages.

• For flights sold on their own, the CAA’s exemption for businesses that pay the airline in full and pass on the ticket straight away does not apply where the airline reserves the right to refuse to carry passengers who did not book with it directly. See flight-only.

Worth knowing

Low-cost is not a legal category, and hybrid airlines blur the line with allocated seats, premium cabins and connections.