A levy had been paid but was found to be a customs charge, contrary to the Treaty. Under Dutch law the period in which it was possible to claim the money back had passed. P argued that since its claim was based on directly effective EC law, national time limits should be disregarded. ECJ rejected P’s argument, saying that in the absence of any relevant Community rules, it is for the national legal order of each Member State to designate the competent courts and to lay down the procedural rules for proceedings designed to ensure the protection of the rights which individuals acquire through the direct effect of Community law, provided that such rules are not less favourable (i.e. equivalence) than those governing the same right of action on an internal matter. The position would be different only if those rules made it impossible in practice to exercise rights which the national courts have a duty to protect (i.e. practical impossibility).