European Union – Customs and excise. The Court of Justice of the European Union ruled that the principle of proportionality had to be interpreted as: (i) not precluding national legislation under which sellers of heating fuel were required to submit, within a prescribed time limit, a list of statements from purchasers that the products purchased were for heating purposes; and (ii) precluding national legislation under which if a list was not submitted within a prescribed time limit, the excise duty applicable for motor fuels was applied to the heating fuel sold, even though the intended use of that product for heating purposes was not in doubt.