Taxation principles are the basis for appropriate and fair taxation. There are two types of tax justice:
1. Horizontal: All are taxed equally, provided they live in the same or similar circumstances.
2. Vertical: People in unequal circumstances are taxed unequally.
Accordingly, tax rates can be proportional or progressive. The basis for the question of justice are the principle of equivalence and the principle of efficiency. In addition, taxation should interfere with economic decisions as little as possible. Another principle of taxation is that the administration of taxes should be simple, efficient and easy to understand.