Tax invoice: It is an invoice issued by one registered vendor to another that shows the amount of account payable. Also, the main purpose of tax invoice is to avail input tax credit. It carries the tax identification number of purchaser. Also it can be issued when goods are sold with the purpose of sale.
VAT invoice: VAT tax is a consumption tax levied on products at every point of sale where value has been added starting from raw materials to final retail purchase by a consumer.
