Which country has highest tax slab?

It is difficult to determine the country with the highest tax slab as tax systems vary greatly between countries and even within countries. Tax rates can also change frequently, so what was true in the past may not be the case now.

However, some countries are known for having high tax rates, such as Denmark, Sweden, and Belgium. These countries have some of the highest tax rates in the world for both personal income and corporate taxes. In these countries, the top personal income tax rate can be over 60% and the corporate tax rate can be over 25%.

It's important to keep in mind that high tax rates do not necessarily translate to high tax revenue, as the effective tax rate (the percentage of tax paid compared to taxable income) can be influenced by various factors, such as tax exemptions, tax credits, and tax avoidance. The overall tax burden (the sum of taxes as a percentage of GDP) is a better indicator of a country's tax system.