Legal analysis: 1. Domestic air tickets: the reimbursement form is the electronic ticket travel itinerary or the air ticket travel itinerary, which is supervised by State Taxation Administration of The People's Republic of China and approved by the Civil Aviation Administration of China. It is used to record the freight rate information and the customer's itinerary, and it is also a ticket reimbursement document. According to national regulations, electronic travel itinerary can only be processed and printed once, so passengers need to keep it properly after processing to prevent it from being lost. Like invoices, electronic travel itinerary, as a kind of reimbursement voucher, is an indispensable document for reimbursement, and does not have the function of security check and check-in procedures.

2. Foreign air tickets: the reimbursement form is a formal invoice.

Legal basis: Measures for the Administration of Air Transport Electronic Tickets in travel itinerary

Article 3 The "travel itinerary" as mentioned in these Measures serves as the payment voucher or reimbursement voucher for passengers to purchase electronic tickets, and also has the function of reminding passengers of their itinerary.

article 4 "travel itinerary" adopts the system of one person, one vote, and is not used as a necessary voucher for airport check-in procedures and security inspection.

article 5 travel itinerary is included in the scope of tax invoice management. Authorized by State Taxation Administration of The People's Republic of China, the Civil Aviation Administration of China is responsible for the printing, purchase, distribution, issuance, storage and cancellation of travel itinerary.