Flat tax is a system of taxation where a constant rate is charged on every source of income regardless of its amount. A flat tax rate applies to every taxpayer, and no deductions or exemptions are allowed. This type of taxation is drastically different from a progressive tax system, where the tax rate increases as a taxpayer's income rises. As a result, a flat tax system is often argued to create a simpler and more transparent system when it comes to tax filing.

Proponents of flat tax believe it gives people an incentive to produce more income and grow their wealth, as people will not be punished for higher wages and income. Since the same rate is imposed on everyone, an individual's motivation for increasing their taxation rate would be absolved. Whereas a flat tax can be seen as potentially 'unfair,' benefitting the wealthy who are able to produce more income and pay the same tax rate, some people also view the flat tax system as entirely 'fair,' ensuring that everyone pays the same percentage of their income in tax.

At the same time, opponents of flat tax argue it unfairly penalizes lower-income earners, who have to shoulder a higher tax burden. In the United States, payroll taxes are the most common form of flat tax applied among lower-income earners. This type of taxation requires employers to match each employee’s Social Security and Medicare contributions as part of the federal payroll taxes. The resulting cost could make it difficult for employees to make ends meet, as the additional payments appear to chip away at employees’ wages.

Overall, flat tax is a system of taxation which has two sides to it. On the one hand, it makes filing taxes easier for people and gives them an incentive to increase their income by not being penalized. On the other hand, it can be argued that the flat tax system hinders more people than it helps, as lower-income earners can’t access the same benefits as those with higher taxable incomes.

It is important for governments to evaluate the pros and cons of implementing a flat tax system. Depending on the country and its current taxation system, a flat tax could help or hinder the population. In order to know the right type of taxation system for the country, an in-depth analysis must be carried out.