What does it cost to book a passenger on another airline?

[Peter47]

How is the payment between carriers calculated when an airline rebooks a passenger on another carrier? Obviously unrestricted fares available at the last minute cost far more than deep discount fares bookable a long way in advance. Presumably airlines don't pay each other the full fare. Are there agreements between airlines as to the settlement or is there some form of clearing house agreement?

The BA dispute with the airline booking passengers onto other carriers got me thinking about this question, but it is likely that there was a negotiated arrangements in this case. Is there is a pre-agreed industry arrangement to cover situations such as a/c going tech, missed connections & overbooked flights?

[Capetonian]

How long is a piece of string?

IATA/carriers in an alliance will often have an agreement between them whereby they will accept a coupon at face value, which would usually mean the prorate value of the coupon based on the through fare in proportion to the sector fares.

Where there is no such agreement coupons are endorsed, usually for a specific value. There are many ways of reaching that, or sometimes none, meaning that the passenger is inconvenienced.

Between LCCs I believe it is done on a one for one basis whereby they will simply give each other credits for 'x' passengers.