Several public transport operators are believed to have systematically invoiced services as having been carried out using electric buses, whereas in reality, a significant portion of these services was allegedly performed using diesel or hybrid vehicles. This practice enabled the operators to benefit from a higher remuneration rate reserved for zero-emission services. Consequently, the required corrective coefficients for not complying with the electrification obligations were not applied either and resulted in overbilling in the period between 2022 and 2024.