Article 273
Member States may impose other obligations which they deem necessary to ensure the correct collection of VAT and to prevent evasion, subject to the requirement of equal treatment as between domestic transactions and transactions carried out between Member States by taxable persons and provided that such obligations do not, in trade between Member States, give rise to formalities connected with the crossing of frontiers. The option under the first paragraph may not be relied upon in order to impose additional invoicing obligations over and above those laid down in Chapter 3.