Opinion of Advocate General Szpunar delivered on 14 December 2023.#Slovenské Energetické Strojárne a.s. v Nemzeti Adó- és Vámhivatal Fellebbviteli Igazgatósága.#Request for a preliminary ruling from the Fővárosi Törvényszék.#Reference for a preliminary ruling – Common system of value added tax (VAT) – Detailed rules for the refund of VAT to taxable persons not established in the Member State of refund – Directive 2008/9/EC – Article 20 – Request for additional information made by the Member State of refund – Information to be provided within a one-month period – Discontinuation of the procedure on account of failure by the taxable person to provide additional information within that time limit – Article 23 – Refusal to take account of information provided for the first time in the appeal procedure – Principle of effectiveness – Principle of VAT neutrality – Principle of good administration.#Case C-746/22.