The popularity of simplified, or “small” business taxes (KATA, KIVA) grows unabated, with thousands of engineers, computer programmers, hairdressers and lawyers opting for one or other of these schemes. Meanwhile, few are fully aware of the risks that these types of tax can entail. The potential consequences are measurable in hard tax forints and penalties, both for payers of these forms of tax and for the businesses that provide their income.