The Swedish environmental protection agency, imposed penalties on the Billerud companies for failing to surrender credits under the EU Emissions Trading Scheme in 2006. The Billerud companies challenged the penalties arguing that since the failure was due to an internal error and the companies had a sufficient number of allowances at the time, they should be excused. The European Court of Justice (CJEU) found that under Directive 2003/87/EZ, penalties for failure to surrender credits still apply even if the entity held a sufficient number of allowances at that time. In addition, the CJEU found that the penalty was a lump sum and may not be varied by a national court on the basis of the principle of proportionality.