Double tax treaty between Poland and Poland – key

On paper, Poland's network of double tax treaties looks straightforward. In practice, applying the correct treaty to a cross-border transaction – identifying residency, source rules, and withholding rates – involves layers of procedural and interpretive complexity that catch even experienced finance teams off guard. A German-owned holding structure with a Polish operating subsidiary, a Ukrainian founder relocating to Warsaw, a Slovak supplier invoicing a Kraków client: each scenario triggers different treaty mechanics, and the wrong analysis can produce double taxation or, worse, a challenge from the Krajowa Administracja Skarbowa (National Revenue Administration, KAS).

Poland's double tax treaties follow the OECD Model Convention and allocate taxing rights between Poland and its treaty partners across income categories including dividends, interest, royalties, and capital gains. The treaties are directly applicable in Polish proceedings and override domestic law where they provide a more favourable outcome for the taxpayer. Withholding tax rates under treaties typically range from 0% to 15%, depending on the income category and the specific bilateral agreement in force.

This guide walks through the key provisions common to Poland's treaty network, the procedural steps for claiming treaty benefits, the three business scenarios most frequently encountered in practice, and the mistakes that generate costly reassessments. It also addresses the interaction between treaty rules and newer Polish tax instruments – including the Ustawa o podatku dochodowym od osób prawnych (Corporate Income Tax Act, CIT Act), IP Box, and transfer pricing documentation – that any tax advisor Warsaw-side must now factor into every cross-border engagement.

What does a Polish double tax treaty actually cover?

Poland has concluded over 90 bilateral tax conventions. Each treaty allocates taxing rights by income category, sets maximum withholding rates, and establishes residency tie-breakers. The National Court Register (KRS) and the Polish Financial Supervision Authority (KNF) do not administer treaty claims directly, but the National Revenue Administration (KAS) enforces compliance and may audit treaty-based positions going back five years. Understanding the scope is the essential first step.

The core provisions cover seven income streams. Dividends paid by a Polish company to a non-resident shareholder are subject to a standard domestic withholding of 19%, but most treaties reduce this to 5% or 15% depending on the shareholding threshold – commonly 10% or 25% of share capital. Interest and royalties carry a domestic rate of 20%, reduced by treaty to 0%–10% in most bilateral agreements. Capital gains on shares in Polish real estate companies can remain taxable in Poland even under treaty, because most modern agreements include a land-rich clause.

Business profits of a foreign enterprise are taxable in Poland only if the enterprise maintains a permanent establishment (PE) here. The PE threshold matters enormously. A foreign contractor sending engineers to a Polish construction site for more than 12 months – or 6 months under some older treaties – creates a PE. That PE then becomes subject to Polish CIT on profits attributable to it. Transfer pricing rules then determine how much profit is attributable, which is where documentation requirements under Polish tax law become binding.

Dividends: domestic 19%, treaty range 5%–15%
Interest: domestic 20%, treaty range 0%–10%
Royalties: domestic 20%, treaty range 0%–10%
Capital gains on real-estate-rich companies: often taxable in Poland
Employment income: taxable where work is performed, with 183-day safe harbour

The treaty also governs the method for eliminating double taxation in the taxpayer's home state. Poland uses both the exemption method and the credit method, depending on the specific bilateral agreement. Under the credit method, Polish-source tax paid reduces the home-state liability but does not eliminate it if the home rate is higher. Taxpayers sometimes assume the exemption method applies when the credit method does – a mistake that produces unexpected home-state tax bills.

How do you claim treaty benefits in Poland step by step?

Claiming treaty benefits is procedural. The payer of Polish-source income – the dividend-paying company, the royalty licensee, the bank – bears primary responsibility for applying the correct withholding rate. If the payer applies a reduced treaty rate without adequate documentation, it faces personal liability for the unpaid tax plus interest at 8% per annum. The process has four stages and must be completed before each payment, not retrospectively.

First, obtain a certificate of tax residency from the payee. This is a formal document issued by the payee's home tax authority confirming residence for tax purposes in the treaty year. Polish tax law requires the certificate to be current – older than 12 months is generally not accepted. For recurring payments, many practitioners refresh residency certificates annually, typically in January.

Second, verify the beneficial ownership of the income. Since 2019, Polish withholding tax rules impose a pay-and-refund mechanism for payments exceeding PLN 2 million per calendar year to a single recipient. Above that threshold, the payer must withhold at the full domestic rate and the payee claims a refund from KAS. The refund procedure takes up to 6 months. This mechanism applies regardless of treaty status and has significantly increased compliance costs for high-volume cross-border structures.

Third, document the substance of the payee. KAS increasingly challenges treaty claims where the payee is a holding company with minimal economic activity. The beneficial ownership analysis requires evidence that the payee has the right to use and enjoy the income, not merely legal title. Board minutes, staff headcount, lease agreements, and bank account activity are all relevant. We secured a full treaty rate confirmation for a Dutch holding structure with a manufacturing client in the Mazowieckie region (autumn 2025), but only after assembling a 40-page substance file.

Fourth, file the relevant WHT declaration with KAS. The declaration is due by the 20th of the month following the payment. Late filing triggers a penalty of up to PLN 720 per declaration under the Kodeks karny skarbowy (Fiscal Penal Code). Where the pay-and-refund mechanism applies, the refund application must be filed separately within 3 years of the payment date or the right is forfeited.

What are the three business scenarios that most commonly arise?

Three transaction types account for the majority of treaty-related queries in Polish practice. Each has a distinct risk profile, timeline, and documentation burden. Understanding the differences helps in-house teams allocate compliance resources before a transaction closes, not after KAS issues an information request.

Scenario 1 – Manufacturing group with a Polish subsidiary. A German parent receives dividends from its Warsaw-based subsidiary. Under the Poland-Germany treaty, the rate is 5% where the German company holds at least 10% of the Polish company's share capital for an uninterrupted 12-month period. If the holding period is not met at the payment date, the 15% rate applies. The 12-month clock resets on any share transfer. Finance teams sometimes miss this when restructuring shareholding before a dividend distribution.

Scenario 2 – IT company licensing IP to a Polish client. A Slovak software company licenses its platform to a Kraków-based client. Under the Poland-Slovakia treaty, royalties are capped at 5%. But if the software is classified as a sale of a standard product rather than a licence of intellectual property, no withholding applies at all – it becomes business profits, taxable only in Slovakia absent a PE. The classification turns on the contractual terms and the degree of customisation. For guidance on how KSeF Poland requirements interact with cross-border software invoicing, see our analysis at what KSeF means for your business in Slovakia.

Scenario 3 – Foreign investor acquiring Polish real estate. A Czech fund acquires shares in a Polish special-purpose vehicle (SPV) holding commercial property. The capital gain on a future exit is taxable in Poland if the SPV's assets consist predominantly of real property situated in Poland – a threshold typically set at more than 50% of asset value. This land-rich clause is now standard in Poland's modern treaties. Proper structuring before acquisition can shift the gain to a treaty-exempt category, but the window closes once the SPV is purchased. For a detailed walkthrough of property acquisition mechanics, see our guide on buying property in Poland.

What mistakes generate KAS reassessments most often?

Most treaty-related tax disputes in Poland share a common thread: the taxpayer applied the treaty correctly in theory but failed on documentation or timing. KAS auditors are trained to look for procedural gaps rather than legal arguments. Four errors appear repeatedly across industries and entity types.

Outdated residency certificates. Applying a treaty rate based on a certificate from the prior tax year is the single most common deficiency. KAS treats an expired certificate as no certificate at all. The payer must then demonstrate it acted in good faith – a difficult standard when the document date is clearly visible. Refresh certificates before each significant payment, not once a year as a formality.

Ignoring the PLN 2 million threshold. The pay-and-refund mechanism is not optional. Payers who continue to apply reduced treaty rates above the threshold without filing for the enhanced due diligence procedure face a 100% surcharge on the underpaid withholding. The mechanism has been in force since 2019, yet we still encounter clients who were unaware of it when entering Poland. The interaction with transfer pricing documentation requirements compounds the risk.

Misclassifying IP payments. Royalties versus business profits versus services fees – the line is not always clear, and Polish domestic law defines "royalties" broadly to include payments for the use of industrial, commercial, or scientific equipment. A payment that qualifies as a royalty in Poland may not be treated as one in the payee's home state. That mismatch can create double taxation that no treaty credit fully eliminates. IP Box planning at the Polish CIT level adds another dimension: income qualifying for the 5% IP Box rate must still be correctly characterised at the treaty level.

We obtained a reversal of a withholding tax surcharge exceeding PLN 1.5 million for a technology client in Lower Silesia (spring 2026), after demonstrating that payments classified as royalties by KAS were in fact service fees under the contractual and economic analysis. The distinction saved the client from the higher domestic rate and the associated interest charge.

Refresh residency certificates annually, before each material payment
Monitor the PLN 2m cumulative threshold per recipient per calendar year
Document beneficial ownership substance – not just legal ownership
Classify income correctly before applying the treaty rate
File WHT declarations by the 20th of the following month

A brief word on family foundations and treaties: the Fundacja rodzinna (family foundation) introduced in 2023 is a Polish resident entity for treaty purposes. Distributions from a family foundation to non-resident beneficiaries may trigger withholding obligations, depending on the characterisation of the distribution under both Polish domestic law and the applicable treaty. This is a developing area and KAS guidance remains limited. Early-stage planning with a tax advisor Warsaw-based is strongly recommended before the foundation structure is finalised.

What to prepare: a practical compliance checklist

Treaty compliance in Poland is not a one-time exercise. It requires ongoing monitoring of payment volumes, counterparty substance, and KAS interpretive guidance. The following checklist covers the minimum documentation set that any cross-border structure should maintain on file before the first payment and throughout the relationship.

Current certificate of tax residency (dated within 12 months of payment)
Beneficial ownership declaration from the payee, supported by substance evidence
Income classification analysis (royalty / service fee / business profit)
Running tally of payments per recipient to monitor PLN 2m threshold
Transfer pricing documentation where intra-group payments are involved

For groups using KSeF Poland-compliant invoicing, the structured invoice data can assist in building the payment tally automatically. For cross-border KSeF implications in neighbouring jurisdictions, see our article on KSeF deadline timeline 2026/2027 for companies in the Czech Republic. Integrating invoice data with WHT monitoring is a practical step that reduces manual error and speeds up any KAS audit response.

The timeline for a full treaty compliance review – covering residency, beneficial ownership, income classification, and WHT filing procedures – typically runs 4 to 6 weeks for a mid-size group with 3 to 5 treaty jurisdictions. Where the pay-and-refund mechanism applies and a refund claim is needed, budget an additional 6 months for KAS processing. Starting that process before year-end allows the refund to be reflected in the same financial year.

A specific situation facing your company carries consequences that become harder to reverse the longer treaty positions remain undocumented. If KAS opens an audit and finds no contemporaneous documentation, the burden of proof shifts entirely to the taxpayer – and the 5-year look-back period means exposure can be substantial.

To receive an expert assessment of your cross-border withholding tax exposure, contact info@kordeckipartners.com.

Frequently asked questions

Q: How long does it take to get a withholding tax refund from KAS under the pay-and-refund mechanism?

A: KAS has up to 6 months to process a refund application filed under the pay-and-refund mechanism. The clock starts from the date of a complete application. Incomplete applications – missing residency certificates or beneficial ownership evidence – are returned without processing, which resets the timeline. Filing a well-documented application at the outset is the most effective way to avoid delays.

Q: Does a Polish family foundation benefit from double tax treaties?

A: A Polish family foundation is treated as a Polish resident entity and can in principle invoke treaty benefits as a recipient of foreign-source income. However, distributions it makes to non-resident beneficiaries may themselves trigger withholding obligations in Poland, and the characterisation of those distributions varies by treaty. This is a common misconception – founders often assume the foundation is treaty-transparent when it is not. Early analysis under the specific bilateral agreement is essential.

Q: Is transfer pricing documentation required for treaty-protected payments?

A: Yes. Treaty protection and transfer pricing compliance are separate obligations. A payment may qualify for a reduced treaty rate and still require a transfer pricing benchmarking study if it is made between related parties and exceeds the statutory thresholds under the CIT Act. Thresholds start at PLN 10 million per transaction category for tangible transactions and PLN 2 million for financial transactions. Failing to prepare documentation by the filing deadline forfeits the right to the simplified safe harbour and exposes the taxpayer to a 10% surcharge on any adjustment.

KORDECKI & Partners is a law firm based in Warsaw and Krakow, advising business clients across 30 jurisdictions. Our team combines expertise in Polish and international law with a practical approach to cross-border tax planning, treaty compliance, and withholding tax advisory. We work with Polish entrepreneurs, foreign investors, and in-house legal teams. To discuss your situation, contact info@kordeckipartners.com.