What type of tax system treats all taxpayers the same regardless of income?

A flat tax system applies the same tax rate to all taxpayers, regardless of their income level. In this system, everyone pays the same percentage of their income in taxes, which means that individuals or entities with higher incomes do not pay a larger proportion compared to those with lower incomes. This approach contrasts with other tax systems like progressive taxation, where higher income earners pay a higher percentage of their income, and regressive taxation, where lower income earners might pay a higher percentage of their income due to a sales tax or similar. Flat taxation is often debated in terms of equity and fairness, as it does not account for the varying abilities to pay among different income groups.