Art. 137. The travel allowance is paid by the competent fund on the basis of an express request from the beneficiary. The request must be accompanied by a copy of the authorization for processing abroad. The travel allowance is always paid to the person transported, or, in the case of a minor, to their legal representative. In the event of presentation of a receipted invoice relating to a means of transport referred to in points 1 to 4 of paragraph 1 of article 132 for which the conditions for taking charge are not met, if it is a question of 'a trip abroad, the travel allowance is automatically paid. The costs for transport services advanced by the beneficiaries are covered on the basis of paid invoices, accompanied by the orders and, where applicable, the required authorizations. Proof that the trip was related to obtaining health insurance benefits in the situations covered by these statutes is incumbent on the beneficiary. Taxi transport costs within the meaning of article 132, paragraph 3 of the statutes are only covered on the condition that the related services are delivered by a supplier approved by the board of directors of the National Health Fund. . Invoices relating to these services are only opposable to health insurance if they contain the following data for each journey made: the name of the company, the number plate of the vehicle used, the date and time of the race, the places of departure and arrival, the mileage and the price invoiced. The air and ambulance transport of the emergency medical aid service in the event of vital distress (degree I emergency) are paid for directly by the National Health Fund through third party payment provided that the emergency situation is recognized. in accordance with Article 132, paragraph 3. Where this last condition is lacking, these transports may be paid for on the basis of paid invoices for simple transport, provided that all the related conditions are also fulfilled. 635 January 2019 Book I The statutory part incumbent on the health insurance of transport services is paid directly to the carrier by the National Health Fund in cases where the latter, at the request of the protected person, has issued prior to transport a cover accepted by the carrier within the framework of the agreements provided for in Article 61 of the Social Security Code or, in the absence of an agreement, within the framework of the conditions of approval regulating the relationship between the National Fund health and carriers.