A flat tax is a tax system where everyone pays the same percentage of their income, regardless of how much they earn. This means that whether someone makes $30,000 or $300,000, they would pay the same tax rate. Proponents argue that flat taxes simplify the tax code and make it easier for individuals to understand their tax obligations. Critics of flat taxes often point out that they can disproportionately affect lower-income earners, as a fixed percentage may take a larger share of their income compared to wealthier individuals. Countries like Estonia and Russia have implemented flat tax systems, sparking debates about their effectiveness and fairness.