Both states can treat you as their tax resident at the same time, and each is right under its own law. The conflict is resolved neither by Ukrainian nor by Polish domestic law, but by the Ukraine–Poland double tax treaty signed on 12 January 1993.
A person left Ukraine in 2022, settled in Warsaw, took a job under a Polish employment contract, rents an apartment and sends the children to a local school. The employer withholds tax and the person files a Polish return every year. From the Polish side the matter looks settled.
What stayed behind in Ukraine: an apartment, a registered place of residence and an open sole trader registration. The business has earned nothing for two years, but no state deregistration has been completed, so the duty to file and pay the single tax remains in force. From the Ukrainian side the matter also looks settled, with the opposite conclusion.
Why Ukraine treats you as a resident
Subparagraph 14.1.213 of the Tax Code of Ukraine sets out a sequence: place of residence, then permanent residence where a home exists in two states, then the centre of vital interests, then presence for at least 183 days, and finally citizenship.
This is why the unterminated sole trader registration is not a household detail but a self-sufficient basis. Ukraine classifies the person as a resident without ever reaching the day count.
Why Poland treats you as a resident
Article 3 of the Polish Personal Income Tax Act sets two alternative tests: a centre of personal or economic interests (ośrodek interesów życiowych) in Poland, or more than 183 days of presence during the tax year. Either one suffices.
- A Polish resident carries an unlimited tax liability and is taxed on all income regardless of source.
- A non-resident carries a limited liability and is taxed only on Polish-source income.
- The person in the example meets both tests at once. The conflict is nobody's mistake: both states applied their own law correctly.
The scale of the phenomenon
There is no precise answer to how many Ukrainians in Poland are simultaneously treated as Ukrainian tax residents, because no authority compiles that statistic. The boundaries can, however, be mapped from adjacent data.
- How many Ukrainians are in Poland. As of February 2026, roughly 966,000 Ukrainian citizens held a PESEL number with UKR status; counting every form of lawful stay, estimates reach about 1.55 million. ZUS recorded roughly 856,000 insured Ukrainians in January 2026. For scale, Eurostat counted 4.33 million Ukrainians under temporary protection across the EU as of 31 March 2026.
- How many keep Ukrainian ties. The Unified State Register listed roughly 2.18 million registered sole traders in January 2026, while the State Statistics Service counted roughly 1.77 million active ones as of 1 October 2025. The gap of about 400,000 records is explained mostly by differing methodologies, but it shows the order of magnitude.
- How many declare foreign income. In the 2026 filing campaign, 12,700 taxpayers declared foreign income for 2025 totalling UAH 20.7 billion: the number of filers rose by 36.6 per cent while the declared amount fell by 39.5 per cent.
Article 4: a sequence, not a checklist
Ownership is irrelevant: a rented flat in Warsaw counts the same as an owned flat in Kyiv. What matters is that the home is continuously available. A hotel does not qualify. Usually a home exists in both states, so this test settles nothing.
The state with closer personal and economic relations. The OECD Commentary points to the totality of circumstances: family, work, administration of property, social and civic activity. Personal ties usually carry more weight.
Time enters the analysis here, but what is assessed is the regularity and continuity of presence over a sufficient period, not the arithmetic of days in a single year.
Nationality applies where the first three tests produce no answer. Where the person is a national of both states or of neither, the competent authorities settle the question by mutual agreement.
In the Warsaw case the sequence stops at the second step: family, work, the children's school and social ties are all in Poland. For treaty purposes the person is a resident of Poland, even though Ukrainian domestic law continues to treat that person as a Ukrainian resident.
Two common configurations
First case: the Ukrainian sole trader registration is kept
| What happens | Consequence |
|---|---|
| The single tax is not among the taxes covered by Article 2 | Poland is not obliged to credit it: the person pays the Ukrainian single tax and full Polish tax on the same income |
| The activity is in fact carried on from a Polish apartment | Real risk of a fixed base (Art. 14) or a place of business (Arts. 5, 7) in Poland: local registration, contributions and filings |
| The registration is retained | It holds Ukrainian residency in place through the presumption in 14.1.213 |
Second case: no registration, but Ukrainian-source income
The ties are weaker and Article 4 is likely to award residency to Poland. Polish treaty residency, however, does not lift Ukrainian income out of Ukrainian taxation: the treaty allocates taxing rights rather than abolishing them.
| Type of income | Article | What follows |
|---|---|---|
| Rent from Ukrainian property | Art. 6 | Taxed in Ukraine regardless of residency. A non-resident may let property only through an authorised person (a Ukrainian sole trader or resident entity) acting as tax agent |
| Dividends | Art. 10 | The source-state cap usually yields no advantage over the Ukrainian domestic rate; check the current text before relying on it |
| Sale of real estate | domestic law | A non-resident is taxed at 18 per cent, while a resident may qualify for an exemption depending on holding period and sequence of sales |
| The Polish side | Art. 24 | Poland taxes worldwide income, but Ukrainian personal income tax is a covered tax and is creditable |
Article 24: how relief actually operates
- The mechanism is a credit, not an exemption, capped at the tax computed under the residence state's own law. Where the source rate is lower, the difference is topped up; where it is higher, the excess is not refunded.
- On the Ukrainian side the same mechanism is mirrored in Article 13 of the Tax Code. Crediting requires a legalised certificate from the foreign tax authority stating the tax paid and the tax base. A bank statement or a copy of the Polish return does not serve that purpose.
- To apply a reduced rate in the source state, a certificate of tax residency must reach the payer before the income is paid: the Polish side expects the Ukrainian certificate, the Ukrainian side the certyfikat rezydencji.
- Whether the treaty extends to the Ukrainian military levy remains contested in practice.
- The treaty is within the scope of the MLI, so any specific article should be read in the synthesised text rather than the 1993 version alone.
Three common mistakes
“I hold a certyfikat rezydencji, so my Ukrainian residency has ended”
It has not. The Polish certificate confirms status under Polish law and is key evidence for applying the treaty, but on its own it does not undo the classification under Ukrainian law, which has no voluntary deregistration procedure for individuals.
“I paid tax in Poland, so there is nothing to declare in Ukraine”
Filing a return and paying tax are separate obligations. Article 24 of the treaty and Article 13 of the Tax Code grant a credit rather than an exemption, and the credit is capped at the Ukrainian tax amount.
“The main thing is not to spend more than 183 days in Ukraine”
A person may stay away from Ukraine for years and remain a Ukrainian resident under the centre of vital interests test, if family members are registered there or a business registration has been kept alive.
What to do in practice
- Decide on the status deliberately. Residency follows from circumstances, but circumstances can be managed, and formal ties all the more so.
- Audit the Ukrainian ties that operate as presumptions: sole trader or self-employed registration, the registered residence of the person and of family members, and Ukrainian sources of income.
- Assemble evidence along the Article 4 tests: a Polish lease, an employment contract, school enrolment confirmations, proof of registered residence. This material is needed two or three years later, when a query arrives.
- Obtain the certyfikat rezydencji for the relevant year and make sure the self-certification given to Polish banks matches the facts: under CRS, account data goes to whichever state the form names.
- Determine in advance how each type of income is taxed under the relevant treaty article and gather the documents needed for the credit, rather than leaving it to filing season.
Conclusion
Dual residency is a condition, not an offence. The tie-breaker rules of Article 4 do not apply automatically: both states continue to treat the person as their resident until that person invokes the treaty and evidences where the centre of vital interests lies. A question settled in advance always costs less than the same question settled in response to a tax query.
Can you be a tax resident of Ukraine and Poland at the same time?+
Yes. It is a normal condition arising from the divergence of domestic rules. The conflict is resolved by the tie-breaker rules of Article 4 of the 1993 treaty, which assign a single state of residence for treaty purposes.
Does a certyfikat rezydencji end Ukrainian tax residency?+
No. The Polish certificate confirms status under Polish law and is key evidence for applying the treaty, but the Tax Code of Ukraine contains no procedure for recording the loss of residency by an individual.
Why does the Ukrainian single tax not protect against Polish tax?+
Article 2 of the treaty lists the covered taxes exhaustively and the single tax is not among them. Poland is therefore not obliged to credit it and taxes its resident's income in full.
Is it really all about 183 days?+
No. The day count is the third test in Article 4 of the treaty and the fourth in subparagraph 14.1.213 of the Tax Code. It is reached only where a permanent home exists in both states and the centre of vital interests cannot be determined.
What is needed to credit Polish tax in Ukraine?+
A certificate from the foreign tax authority stating the amount of tax paid and the tax base, legalised in the prescribed manner. A bank statement, a payslip or a copy of the Polish return does not qualify.
