Article 20 mandates each Member State to establish an electronic services system for tax compliance. It directs the GCC Secretary General to create a central tax information centre and an electronic system to monitor Internal Supplies and facilitate information exchange between tax authorities. This system must record specific details, including the Tax Identification Numbers of the supplier and customer, tax invoice information, and transaction value. A confirmation number is issued when data matches, serving as proof for tax audits. The system must be secure, providing tax administrations with access to Intra-GCC supply data and enabling the tracking of goods to their final destination.