The request takes the form of a reasoned opinion (the second step of the infringement procedure provided for in article 226 of the EC Treaty). If the relevant national legislation is not amended within two months in order to comply with the reasoned opinion, the Commission may refer the matter to the European Court of Justice.

The Commission believes that certain national anti-fraud provisions do not comply with the EU legislation on the movement and holding of goods subject to excise duties, since they introduce a burden on traders that is disproportionate to the objective pursued.

Portugal requires that the 'accompanying administrative document' is sent to the competent customs office at least six hours before the departure of the products which are subject to excise duties from warehouses in its territory. The Commission is of the opinion that the relevant Community legislation (Article 19 of Directive 92/12/EEC) cannot be interpreted as allowing Member States to impose such condition.

The Portuguese legislation is likely to jeopardize the correct operation of the internal market with regard to these products and cannot be justified as a necessary mean to avoid tax fraud.

Further to the above, according to Portuguese Law, authorized warehouse keepers have to provide a guarantee in connection with the holding of products subject to excise duty. The guarantee amounts in general to 2% of the average monthly amount of excise duty paid during the previous year, with a minimum and a maximum threshold.

The Commission has argued that this holding guarantee is disproportionate to the aim pursued (namely, to secure the revenue potentially at risk) and may act as an effective barrier for traders wishing to enter into the Portuguese market.