Deemed income (tekmiria)
Rules under which the tax authority treats you as having income based on your assets or lifestyle, even if you declared less.
Deemed income rules let the tax authority estimate income from signs of wealth or spending, such as property, cars, boats, a pool or household costs.
If your declared income is lower than the deemed amount, the difference is taxed. Check the deemed-income rules before filing a low-income return while owning significant assets.
Official source: AADE (Greek tax authority)