The European Insolvency Regulation, introduced in May 2002, was designed to assist in European cross-border insolvencies by creating a system of recognition and priority across the European member states. It was founded upon the concepts of 'main proceedings' and 'secondary proceedings' and introduced new concepts which have had to be interpreted by the courts. Perhaps the key example of these is determining where the centre of main interests (COMI) of a debtor lies under the regulation.

The COMI of a debtor is important because it is only in the member state in which a debtor's COMI lies that main proceedings may be opened under Article 16 of the regulation. Main proceedings are made paramount by the regulation – there can only be one set of main proceedings, and the applicable law is that of the member state in which they are opened. Once a court in a member state has opened proceedings, they must be recognised by all member states.

How should COMI be identified? To assist, recital 13 to the regulation says COMI should "correspond to the place where the debtor conducts the administration of his interests on a regular basis and is therefore ascertainable by third parties". There is a rebuttable presumption – which can only apply to companies – that COMI will be where the debtor has its registered office. One might have thought the test of external ascertainability under recital 13 would have meant the location of COMI for a particular debtor would be obvious to whichever court was making the assessment, and there would be no room for disagreement. In practice, however, courts in different member states have not always agreed about how the test for COMI should be applied.