Judgment of the Court (Eighth Chamber) of 3 September 2020.#Delfly sp. z o.o. v Smartwings Poland sp. z o. o., formerly Travel Service Polska sp. z o.o.#Request for a preliminary ruling from the Sąd Rejonowy dla m.st. Warszawy w Warszawie.#Reference for a preliminary ruling – Air transport – Regulation (EC) No 261/2004 – Article 7 – Right to compensation in the event of delay or cancellation of a flight – Compensation procedure – Claim expressed in national currency – National provision prohibiting the creditor from choosing the currency.#Case C-356/19.