Case C-121/24, Vaniz: Judgment of the Court (Sixth Chamber) of 11 December 2025 (request for a preliminary ruling from the Administrativen sad Veliko Tarnovo – Bulgaria) – Vaniz EOOD v Direktor na Direktsia Obzhalvane i danachno-osiguritelna praktika – Veliko Tarnovo (Reference for a preliminary ruling – Common system of value added tax (VAT) – Directive 2006/112/EC – Article 205 – Joint and several liability – Insolvency of the principal debtor – Continued obligation to pay VAT – Joint and several liability of a third party after the removal of the principal debtor from the commercial register – Principle of legal certainty – Principle of proportionality)