3. Member States may allow hydrogen network operators to spread the recovery through network access tariffs of hydrogen network costs over time in order to ensure that future users duly contribute to initial hydrogen network development costs. Such an inter-temporal cost allocation and its underlying methodology shall be subject to approval by the regulatory authority. Member States may put in place measures, such as a State guarantee, to cover the financial risk of hydrogen network operators associated with the initial cost recovery gap arising from the application of inter-temporal cost allocation provided that such measures comply with Article 107 TFEU.