The calculation of VAT is a complicated operation. Different stages of the manufacturing and distribution process add value, and tax must be charged accordingly. For raw materials, work in progress, and finished products, there are different tax measurement rules. When a company buys the same raw material from different suppliers, such as a furniture company buying the same Mahogany wood from different sellers at different rates, the tax estimate would be different in each case. For convenience, a company that normally manufactures a product from scratch may decide to purchase more processed material. For example, an ice-cream company that normally buys raw materials such as milk and cocoa powder separately might start buying processed chocolate milk at the same time for production convenience. The VAT estimation will be difficult in this situation. Using Vat software such as SmartVAT can make the process much more effective and simple.