In a new study commissioned by the Federal Environment Agency (UBA) FiFo-researchers use improved data sets to quantify the tax benefits enjoyed by company car users under the so-called ‘1 per cent rule’. For 2024, the blanket rule is associated with a shortfall in tax revenue of 4.2 billion euros, as well as approximately 1.68 million tonnes of additional CO₂ emissions. The study represents a methodological improvement by examining the effects of vehicle provision and use separately. From a tax policy perspective, the move to a '1.7 per cent rule' is recommended.