The billing items of travel agencies usually include the following aspects:

1. Tourism product costs: including the costs of various tourism products (such as tourist routes, hotel reservations, transportation tickets, etc.) provided by travel agencies.

2. service fee: the service fee provided by the travel agency for passengers, such as travel insurance, tour guide service, travel consultation, etc. These fees are generally fixed or calculated in proportion.

3. train ticket fee: if the travel agency purchases the train ticket, it will take the train ticket fee as one of the invoicing items.

4. air ticket fee: if the travel agency booked the air ticket, the air ticket fee will be one of the invoicing items.

5. Food and beverage expenses: The food and beverage expenses during the trip may also be listed in the billing item, and the specific expenses will depend on the travel arrangement and contract.

6. Admission ticket fee: If the travel agency includes the scenic spot ticket fee, it will be listed in the billing item.

It is worth noting that the billing items will be different according to the business scope of the travel agency, the contract agreement and the specific content of the travel products. When you buy travel products, you should confirm the billing items with the travel agency clearly, and clearly list all expenses and services in the contract to ensure the subsequent financial and legal rights and interests.