In Vietnam, unlike many other countries, invoices must be purchased in advance. Since 2019, it is mandatory for new companies to use electronic invoices (e-invoices). These are called “red” invoices or VAT invoices or “hóa đơn đỏ”. In other countries (except China), any document titled “invoice” can be used and considered as an invoice. In Vietnam, such as in China, the invoices system is centralized and each company must purchase a number of invoices that will be used when they want to “declare” a business or a transaction. It also means that if you do not issue an VAT invoice, your transaction will not be registered by the government therefore not accounted.