在许多发展中国家，税收总收入有三个主要来源：对商品和服务收取的国内税（销售税和消费税 ） 、 直接税（主要对公司收取）以及最重要的对外贸易税（进口关税 ） 。
In many developing countries, total tax revenue is derived from three main sources: domestic taxes on goods and services (sales and excise taxes), direct taxes (primarily on corporations), and, most important, taxes on foreign trade (import duties).