The sales VAT registry is a component of the accounting system for entrepreneurs who are VAT payers. Keeping such a registry is essential for the correct settlement of VAT and for meeting legal requirements (Act of 11 March 2004 on VAT). Its purpose is to: Document transactions – enables recording all sales of goods and services, which is necessary to calculate the output VAT due. Facilitate settlements – helps prepare VAT declarations and calculate amounts payable or deductible. Meet legal requirements – entrepreneurs are obliged to keep the registry in accordance with tax law.