Article 70 mandates the exchange of information between the Tax Administrations of Member States for the implementation of the Agreement and enforcement of local VAT laws. This information is confidential and its disclosure is strictly limited to authorities involved in tax assessment, collection, and legal proceedings. A state is not obliged to provide information if it contradicts its administrative practices, is unobtainable, or would reveal trade secrets. However, a state must collect requested information even if not required for its own tax purposes and cannot refuse a request solely because the data is held by a financial institution.