A special value-added tax system has been added as part of the Medad system. The system computes value-added tax in all sales, purchases, returns and supplies of all kinds. The system allows the facility to define the items for which the value-added ratio is calculated in the basic ratio, the exempt items, and the items whose percentage is zero. The system also allows determining the type of dealings with the customer and the supplier and whether operations with each customer or supplier are subject to value-added tax or not. The system also prints sales invoices with the required data according to the requirements of the Zakat and Income Authority. Through the system, it is possible to issue a tax return report and know the amount of tax to be paid or due to be recovered from the Zakat and Income Authority.