Request for a preliminary ruling from the Bundesfinanzhof (Germany) lodged on 8 September 2021 — Hauptzollamt Hamburg v Shell Deutschland Oil GmbH

(Case C-553/21)

(2021/C 490/21)

Language of the case: German

Referring court

Bundesfinanzhof

Parties to the main proceedings

Appellant in the appeal on a point of law: Hauptzollamt Hamburg

Respondent in the appeal on a point of law: Shell Deutschland Oil GmbH

Question referred

Does the principle of proportionality under EU law apply also to the optional tax reduction provided for in the fourth indent of the first sentence of Article 5 of Directive 2003/96/EC, (1) such that the Member State may not refuse to grant the tax reduction after the period for making an application under national law has expired, if assessment has not yet been time-barred at the time the application is received by the competent authority?

(1)  Council Directive 2003/96/EC of 27 October 2003 restructuring the Community framework for the taxation of energy products and electricity (OJ 2003 L 283, p. 51).