Greek sourced income is any income from a Greek source and especially (par.1, art.5 ITC):

a) income from employment exercised in Greece, as well as income from employment exercised abroad and paid by Greek State,

b) income from pensions paid by the Greek State, by a domestic main and supplementary entity for mandatory insurance, as well as by professional funds established by law in Greece,

c) income from administrative, consulting and technical services provided in Greece, through a permanent establishment, 

d) income from artistic and sports activities provided in Greece,

e) income from business activity performed in Greece through a permanent establishment,

f) income from the sale transfer of immovable property by a foreigner performing business activity through a permanent establishment in Greece,

g) income from immovable property and income from other rights resulting from immovable property, provided that the immovable property is located in Greece,

h) income from the sale of immovable property located in Greece,

i) income from the sale of an entire business, company shares or holdings, stocks, listed or non-listed bonds and financial derivatives, provided that the above securities have been issued by a Greek enterprise,

j) income from dividends or other distributed amounts by a legal person with Greek tax residency,

k) income from dividends or other distributed amounts by legal entities with Greek tax residency,

l) income from interest paid or credited that is due by a Greek tax resident or by a non-resident through a permanent establishment in Greece,

m) income from royalties credited or paid by a Greek tax resident or by a non-resident through a permanent establishment in Greece.

Greek sourced income is taxed by income category in the same way whether they are acquired by Greek tax residents or by non-residents. In cases where the non-resident who acquires Greek sourced income is tax resident of a country with which Greece has concluded a DTA, the provisions of the relevant Agreement are applied, due to increased formal validity.

Important Note! Taxpayers who do not have their tax residency in Greece are not entitled to tax reductions for employment and pensions income, unless: 
a) they maintain their tax residence in another EU or EEA member state and at least ninety percent (90%) of their worldwide income is Greek sourced, or
b) they prove that their taxable income is so low that they would be entitled to a tax reduction under the tax legislation of their state of residence (Article 20 of the ITC).

The tax exemption of salaries, pensions and fixed remuneration granted to disabled people with a disability rate of at least eighty percent (80%), also applies to foreign tax residents.

Important Note! Non-Greek tax residents are subject to alternative minimum taxation, only on their presumptive income calculated on the basis of the assets acquisition cost and only if they obtain real income in Greece (e.g., if a non-Greek tax resident obtains income from interest on deposits in Greece and purchases an immovable property). They are not subject to alternative minimum taxation on their presumptive income calculated on the basis of objective living cost (Article 33 of the ITC).