(14)Companies and their branches opened in other Member States should have a unique identifier allowing them to be unequivocally identified within the Union. The identifier is intended to be used for communication between registers through the system of interconnection of registers. Therefore, companies and branches should not be obliged to include the unique identifier in the company letters or order forms mentioned in Directives 89/666/EEC and 2009/101/EC. They should continue to use their domestic registration number for their own communication purposes.