What expenses related to tickets and additional fees are covered by the employer during business travel and what documentation is needed to recognize those expenses for tax purposes?

The amount of the purchased ticket and additional fees incurred, such as checked-in luggage fees when traveling by plane are covered by the employer. The invoices for the respective purchases, should be issued in the name of the company. For air travel, submission of the ticket and boarding pass in both directions is required; for bus or train travel, submission of the ticket is necessary.