The TicketExchange transaction serves the purpose to exchange existing tickets against other ones.

The existing ticket can be more, equal or less expensive than the new ticket. So additional collections or refunds can be necessary.

Exchanges are a two step process. First of all a TicketExchangeRQ is sent that prepares the PNR for the exchange and returns an ExchangeRequestNumber. The value of this ExchangeRequestNumber field is then passed to a following TicketIssueRQ, that is to be sent in order to issue the actual exchange ticket.

Exchanges can only be performed with one FareGroup as TicketIssue. It is not possible to use parts of the FareGroup for ticket exchanges.

There are different modes of exchange:

• Full Exchange: The original ticket or parts (coupons) of it has not already been flown.
• Partial Exchange: Partial exchanges are exchanges of parts of an original ticket (where one or more of the original segments have been flown or flight coupons have been used) for a new ticket.  

There are different types of exchange:

• Even exchange: The amount of the existing ticket will be used for the new ticket. No additional charge or refund.
• Additional collection exchange: The amount of the exchange ticket and an additional charge are necessary to pay the new ticket. This may be an additional fare amount, an airline imposed change fee or both.
• Residual exchange: The new ticket is cheaper than the old ticket, so the remaining amount will be paid back.