36In so far as, as the Czech Government essentially submits, the failure to place goods intended for exportation under that customs procedure could often have the effect of making it more difficult, or even impossible, for the tax authorities to ascertain that the goods have actually left EU territory, it is indeed true that, as regards the production of conclusive evidence referred to in paragraph 35 above, the fact of exportation must be established to the satisfaction of the competent tax authorities, that requirement relating to the substantive conditions necessary for the exemption to be granted (see, to that effect, judgment of 8 November 2018, Cartrans Spedition, C‑495/17, EU:C:2018:887, paragraph 48).