[2] It was formed in 2005 in response to European Union requirements to separate the natural monopoly of infrastructure management from the competitive operations of running train services.

[7] Between 2016 and 2021, ADIF undertook a protracted and complicated process under which it implemented numerous free market-orientated models to replace ones favouring the state-owned Renfe.

[9] Following these changes, three different companies had signed ten-year agreements on the provision of various high-speed services, including on the Madrid-Barcelona, Madrid-East and Madrid-South routes, by early 2023.

[8] During 2021, the Comisión Nacional de los Mercados y la Competencia (CNMC), Spain's competition regulator, imposed fines totalling €127.3m on various infrastructure supplies, including Alstom, Bombardier Transportation, CAF Signalling, Cobra, Nokia, Siemens Rail, and Thales, for their involvement in a cartel that fraudulently inflated the prices of bids issued for at least 82 tenders by ADIF, the Ministry of Development, and the former Railway Infrastructure Manager (GIF), related to the construction, execution of works, supply, installation, commissioning and maintenance of security and communications apparatus on Spain's railway network.

During July 2023, following a competitive tendering process, the international auditing company Deloitte was awarded a contract to develop a new scale for the calculation of these access charges that were applied to operators, such as Renfe, Iryo and Ouigo, for the first time in the following year.