In Poland, interest from a domestic bank account or brokerage is taxed at source: the bank or broker calculates and withholds it. Interest from a foreign P2P lending platform is different — no Polish withholding agent exists, so the investor must calculate the taxable amount and report it in their annual tax return.
Poland tax on foreign P2P interest: who files what and when
In Poland, interest from a domestic bank account or brokerage is taxed at source: the bank or broker calculates and withholds it. Interest from a foreign P2P lending platform is different — no Polish withholding agent exists, so the investor must calculate the taxable amount and report it in their annual tax return.
This article is not tax advice. It is written for the 2026 Polish tax year and reflects the framework reviewed as of 24 September 2026. Tax treatment depends on residence status and personal circumstances, and the applicable instructions should always be verified on podatki.gov.pl before filing.
Who Pays Tax on Interest in Poland: Bank, Broker, or You?
The key difference is who acts as the withholding agent.
With a Polish bank deposit or brokerage account, the institution generally handles the withholding linked to the interest payment. With a foreign P2P platform, that Polish payer role may be absent. The investor then has to identify the relevant interest, convert it into PLN under the rule for the tax period, and report it.
Maclear is an example of a Swiss foreign platform in this context. It is not a Polish withholding agent or tax adviser. Maclear is a member of PolyReg SRO and operates under Swiss financial regulations.
Does a Foreign P2P Platform Withhold Polish Tax Automatically?
Usually, no. A foreign P2P platform should not be assumed to withhold Polish tax in the same way as a domestic bank or broker.
If no Polish withholding agent is involved, the investor remains responsible for checking the applicable rules, calculating the reportable amount, and filing it correctly. The exact treatment should be verified against the official Polish guidance for the tax year concerned.
What Counts as Taxable Income on a Foreign Platform Statement?
A platform statement can contain several movement types that should not all be treated as interest income.
Income source | Withholding agent present | What the investor must do | Timing |
Interest on a Polish bank deposit | Yes | No separate withholding calculation by the investor | When interest is credited |
Interest via a Polish brokerage account | Yes, where the broker acts as payer | Usually no separate withholding calculation for that payment | When interest is credited |
Interest from a foreign P2P platform | No Polish withholding agent assumed | Report the interest amount in the annual declaration | When the payment is received, not when the investment is made |
Return of principal | Not an income payment | Separate it from interest | Not treated as an interest event |
Sale of a claim on the Secondary Market | Case-specific | Check the treatment of a sale at par or at a discount of up to 50%; do not treat it automatically as ordinary interest | At the transaction date |
Loss on a defaulted claim | No ready-made withholding treatment | Do not assume the loss is automatically deductible; verify current official guidance | When the relevant loss event is recognized |
This table describes reporting mechanics as of the publication date. It does not provide a tax rate, form number, or declaration field. Those details should be checked on podatki.gov.pl for the specific tax period.
Is the Repayment of My Principal Taxable?
The return of principal is not the same as interest income. It is the return of capital previously invested.
That distinction matters when reconciling the annual statement. Interest, principal repayments, Secondary Market transactions, and default-related movements should be kept separate so the investor does not inflate the amount treated as investment income.
How to Convert Foreign-Currency Interest for Polish Tax Purposes
Foreign P2P platforms may pay interest monthly and in a currency other than PLN. Each payment therefore needs to be converted separately under the official PLN conversion rule applicable to the date the income is received.
Do not total a year's foreign-currency interest and convert it once using a single year-end rate. Monthly payments occur on different dates, so the applicable conversion can differ from one payment to the next.
The source for the conversion rule should be the official national guidance rather than a platform rate, exchange rate feed, or informal calculator.
Which Exchange Rate Date Applies to a Monthly Interest Payment?
Use the date relevant to receipt of that specific interest payment and then apply the official exchange-rate convention required for the tax period.
Do not use the original investment date and do not apply one year-end rate to all monthly payments. Before filing, verify the exact date convention and official rate source on podatki.gov.pl.
What to Export From the Platform for Your Annual Declaration
Start with a statement or CSV covering the full tax year and keep the movement types separated.
Retain:
each interest payment, with date and amount;
each principal repayment;
each Secondary Market sale;
each default-related write-down or loss entry;
the PLN conversion calculation used for each interest payment.
Keep the original statement and the FX calculation separately from the final annual figure. This makes it possible to reconstruct how the reported amount was calculated if it later needs to be checked.
The date of every monthly interest payment is particularly important because the conversion should be performed payment by payment rather than from one year-end total.
What Happens If Foreign Platform Interest Isn't Declared?
Foreign-platform income should not be assumed to sit outside the Polish tax authority's information environment.
The practical risk is that omitted reportable income may later need to be corrected, with additional tax consequences depending on the circumstances. Automatic exchange of financial information also means that foreign financial activity should not be assumed to remain outside the tax authority’s information environment.
That does not mean every P2P transaction is necessarily exchanged under the same reporting mechanism. It means the investor should not rely on the assumption that foreign financial activity is invisible.
What Happens If I Forget to Declare Foreign Interest Income?
The investor may face an additional assessment and may need to correct the annual filing. The exact consequence depends on the facts and the rules in force for the relevant period.
Because information on foreign financial activity can be exchanged between jurisdictions, relying on the assumption that foreign interest will not be visible is not a sound approach. Check the current correction procedure on podatki.gov.pl.
Does the Platform's Location Change Who Calculates the Tax?
No, not by itself. The platform's country does not remove the investor's reporting responsibility where no Polish withholding agent has already calculated and withheld the relevant tax.
What matters is whether tax was withheld, whether any foreign tax was paid, and how the Polish rules for that income apply to the investor's circumstances.
Maclear is a Swiss platform and serves here only as an example of a foreign P2P platform without Polish withholding at source. Its Swiss regulatory status does not make it a Polish tax adviser or transfer the filing obligation away from the investor.
Assuming a foreign platform withholds Polish tax the way a domestic bank does is a common and costly mistake — verify the correct exchange-rate rule and your reporting obligation directly on podatki.gov.pl before filing.
Key takeaways
- A Polish bank or broker acts as withholding agent; a foreign P2P platform generally does not, so the investor calculates and reports the amount.
- Each interest payment is converted into PLN under the official rule for its own payment date, not with one year-end rate.
- Principal repayments, Secondary Market sales and default write-downs are separated from interest before the annual figure is prepared.
- The export kept for the file should include every payment date, amount and the conversion used, so the reported figure can be reconstructed.
- Automatic exchange of financial information means foreign platform income should not be assumed to be invisible to the tax authority.
Frequently Asked Questions
Does a foreign P2P platform withhold Polish tax automatically?
Usually, no. A foreign P2P platform should not be assumed to perform the same withholding role as a Polish bank or broker. If no Polish withholding agent is involved, the investor is responsible for identifying the relevant interest income, applying the correct PLN conversion, and checking how it must be reported for the tax period being filed.
Is the return of my principal taxable in Poland?
Principal repayment is the return of capital previously invested, not interest income. It should therefore be separated from interest when reviewing a platform statement. This does not resolve every possible tax issue around a sale, discount, or default loss, so transaction-specific treatment should still be checked under the official Polish rules for the relevant tax year.
Which exchange rate applies to interest paid in a foreign currency?
Use the official PLN conversion rule tied to the date that each interest payment is received. Do not use the original investment-date rate and do not apply one year-end rate to all monthly payments. The exact exchange-rate convention and official source should be verified on podatki.gov.pl for the tax period covered by the declaration.
What should I export from the platform before filing my declaration?
Export the annual statement or CSV with transactions separated by type. Keep the date and amount of every interest payment, principal repayment, Secondary Market transaction, and default-related entry. You should also retain the PLN conversion used for each foreign-currency interest payment so the annual figure can be reconstructed if it is later reviewed.
What happens if I don't declare interest from a foreign platform?
An omitted reportable amount can lead to additional tax being assessed and may require a correction of the annual filing. Information on foreign financial activity may also be exchanged between jurisdictions. The exact consequences depend on the circumstances, so any omission should be checked against the current Polish tax guidance for the relevant tax period.
This article is not tax advice. Polish tax obligations depend on residence status, personal circumstances, and the rules applicable to the tax period concerned. Before filing for the 2026 tax year, verify the current instructions on podatki.gov.pl and, where needed, consult a qualified Polish tax professional.
Related articles
- Germany: Anlage KAP
- Portugal: Anexo J
- Italy: Quadro RW
- Automatic Exchange of Information: Does Your Tax Office Know?
About Maclear
Maclear AG is a Swiss-based P2P lending and crowdlending platform headquartered in Switzerland. The company operates as a financial intermediary in the non-banking sector and is a member of PolyReg SRO, in compliance with Swiss financial regulations including AML, KYC, and GDPR. Maclear offers retail and qualified investors access to vetted business loan opportunities, with built-in risk assessment, a Provision Fund, and a Secondary Market for liquidity.
The content of this article is provided for informational and educational purposes only. It does not constitute investment, financial, tax, or legal advice. P2P lending and crowdlending investments carry a risk of partial or total capital loss. Past performance is not indicative of future results. Liquidity on a secondary market is not guaranteed. Readers should conduct independent research and consult qualified advisors before making any financial decisions. Availability of products and services may be restricted in certain jurisdictions.