Foreign Income in Poland: Avoiding Double Tax (PIT-36, PIT/ZG)
Short answer: Polish tax residents declare worldwide income. Double tax is avoided by exemption with progression or proportional credit, set by the treaty. Use PIT-36 with PIT/ZG for each country.
If you live in Poland but also earn money in another country, or you worked abroad for part of the year, Poland may still want to tax that income. The question is whether you pay twice. This guide follows the official Polish returns portal for people coming back to Poland (powroty.gov.pl), whose page "Rozliczenia podatkowe a dochody z więcej niż jednego kraju" states it reflects the legal position as of 18 May 2026. Check it again before you file, because tax rules change at the start of each year. The page speaks of Polish tax residents in general, not of any nationality, so it applies to foreigners who are Polish tax residents as well.
Where you are taxed depends on residence
According to the portal, the place where your income is taxed depends on the country where you have your tax residence. If you are not a Polish tax resident, you pay tax in Poland only on income earned in Poland (limited tax liability). If you are a Polish tax resident, you must declare all your income in Poland, wherever it came from (unlimited tax liability). Because the other country may tax the same income, one of two methods is used to avoid double taxation. Which one applies is set by the double taxation treaty between Poland and that country, or by the PIT act if there is no treaty.
Method 1: exemption with progression
Under this method the income earned abroad is excluded from the Polish tax base, but it still affects the tax rate on your other income taxed in Poland. The portal says it can apply only where Poland has a treaty with the country, and names Germany as an example of a treaty that uses it for employment income.
If all your income is foreign and exempt in Poland under the treaty, you do not have to file a return. If you also have other income taxed on the tax scale in Poland, or your spouse does and you want joint filing, you must file and use this method.
The portal's worked example: Polish income 20,000 zł and foreign income 30,000 zł, total 50,000 zł. Polish tax on 50,000 zł by the scale is 2,400 zł, which is 4.8% of the total. You pay 4.8% on the 20,000 zł earned in Poland, so 960 zł, minus any advance payments already withheld in Poland.
Method 2: proportional credit
Under this method the foreign income is taxed in Poland, and you deduct the tax paid abroad from the Polish tax. The deduction is limited to the part of the Polish tax that falls proportionally on the foreign income. The portal says it names Austria, the Netherlands, Kazakhstan, Slovenia and the United States as examples of treaties using it, and that it also applies where there is no treaty (it gives Iraq, Libya, Afghanistan and Brazil as examples) or where the treaty does not cover the territory, such as Hong Kong. With this method you must always show foreign income in your annual return.
The portal's example: Polish income 30,000 zł, foreign income 20,000 zł, 5,000 zł tax paid abroad. Total income 50,000 zł, Polish tax 2,400 zł. The most you can deduct is 2,400 zł x 20,000 / 50,000 = 960 zł. Polish tax to pay is 2,400 - 960 = 1,440 zł, minus advances withheld in Poland. The portal notes its examples only show how the methods work and are not a comparison of them.
If you stay abroad temporarily and earn from work there, you must also pay an advance of 12% of that income (or a higher rate from the scale) by the 20th day of the month after the month you returned. If that deadline falls after the end of the tax year, the tax is due when you file the return.
The abolition relief
Under article 27g of the PIT act, you can deduct from your tax the difference between the tax calculated by the proportional credit method and the tax calculated by the exemption method on the same foreign income. This is called "ulga abolicyjna". The portal says that since 1 January 2021 it is capped at 1,360 zł, with exceptions for certain income from work or services performed outside the land territory of states. You report it in the PIT/O attachment.
Which forms
If your foreign income is exempt in Poland under a treaty but you also have other income taxed on the scale (or want joint filing with your spouse), or if your foreign income is not exempt, file PIT-36 with the PIT/ZG attachment. You file a separate PIT/ZG for each country. If you are abroad, you can file the return at a Polish consulate before the deadline, or post it to your tax office. The deadline counts as met if you post it at a Polish public postal operator before it ends.
* Photos: passport entry stamp and a 1941 tax form (public domain), Wikimedia Commons. Illustrative.
Frequently asked questions
Do I have to file a Polish return if my foreign income is exempt under a treaty?
Not if all your income is foreign and exempt in Poland. If you also have other income taxed on the scale, or you want joint filing with your spouse, you must file and use the exemption with progression method.
Which form shows foreign income in Poland?
The portal says to use PIT-36 with a PIT/ZG attachment for each country, and PIT/O if you claim the abolition relief.
