Reporting and carrying forward a forex loss in Poland

A qualifying private derivative loss reported under Polish Article 30b(1) may reduce eligible income in the five following tax years, subject to Article 9(3) and (6). It reduces income, not tax directly, and does not guarantee a refund or future gain. Track the original year, amount, unused balance and available deduction route separately.

Is a forex loss tax-deductible in Poland

The model concerns a Polish resident’s private CFDs correctly classified under Article 30b(1), rather than transactions in business activity. Combine only revenue and eligible costs that the relevant rules permit to be combined. A current-year PLN 12,000 gain at one broker and PLN 5,000 loss at another in this category give PLN 7,000 income before prior-year deductions. Dividends and interest under Article 30a and virtual-currency disposal have separate rules; appearing on PIT-38 does not permit unrestricted offsetting.

Three rules to memorize before your first filing:

• Five consecutive tax years. A loss from 2024 may be used against eligible income for 2025 through 2029. The return for the final usable tax year is normally filed in 2030; do not confuse the income year with its filing season.
• Two deduction routes to choose from. The default one: at most 50 percent of the loss amount in any single one of those years, with the remainder carried forward. The alternative, available for losses incurred from 2019 onwards: a one-off reduction of income in one of the five years by up to 5 million PLN, with anything left over falling back to the fifty-percent rule in the remaining years.
• Within the eligible category only. Check Article 9(6) and the actual source before offsetting. Qualifying private CFD losses do not simply reduce salary, business or rental income, Article 30a dividends/interest or virtual-currency income.

Reporting an eligible loss does not itself create a tax refund. Keep the calculation and filed return to support later deductions. If a required return was missed or a loss omitted, examine a late original filing or a permitted correction; the missed deadline alone does not establish permanent forfeiture.

How the fifty-percent cap works in practice

Hypothetical example, not tax advice. Assume a correctly established PLN 20,000 eligible loss in 2024 and PLN 8,000 eligible income in 2025 after tax-deductible costs. The basic tax before carryforward is 8,000 × 19% = PLN 1,520. No platform fee is assumed deductible merely because it was paid.

The annual 50% cap remains PLN 10,000 because it uses the original PLN 20,000 loss. In 2027, however, only PLN 6,000 remains unused, so the deduction cannot exceed PLN 6,000 even though eligible income is PLN 9,000. Check all three limits together: current income, unused loss and the chosen route’s statutory cap.

In this example the choice between the two routes changes nothing, because every annual gain is smaller than half the loss, so the deduction is limited by current-year income anyway. The one-off route only starts to matter when a single year brings a gain larger than half the loss: with a 100,000 PLN loss and 100,000 PLN of capital-source income in one of the five years, the whole thing can be written off at once instead of being spread across two years at 50,000 PLN each. With annual gains in the low tens of thousands, a large loss can still expire before it is fully used — the five-year window cannot be extended.

Filling in PIT-38 with a loss step by step

The mechanics, whether you use the Twoj e-PIT pre-filled portal or work through the paper form yourself:

1. Gather the actual documents. Check each contracting entity’s PIT-8C obligation and statement coverage. For 2025, the taxpayer deadline moved from the end-of-February Saturday to 2 March 2026. If no PIT-8C is supplied, use sufficient source records; provider branding or foreign registration alone does not settle document availability.
2. Use the form for the correct tax year. In the 2025 PIT-38 version, Part C records Article 30b(1) revenue, costs, income and loss; Part D calculates that source tax. Convert foreign-currency amounts at the average NBP rate from the working day preceding the relevant revenue or cost event.
3. In the 2025 PIT-38 version, current Article 30b(1) loss is reported in Part C. Part E is the separate virtual-currency section. Document the original loss and its five subsequent usable tax years.
4. In the 2025 PIT-38 version, eligible prior-year Article 30b(1) losses are deducted in Part D, field 30, within the statutory annual and remaining-loss limits and available current income. Use the version for the year you are filing.
5. File the required complete return by the applicable deadline and retain confirmation. Prepared Twój e-PIT data may be incomplete. If a loss-year return was missed, investigate the correct late-filing route instead of assuming automatic permanent forfeiture.
6. Retain the loss and deduction trail. Keep returns, UPO, statements, conversion records and evidence of costs and prior deductions. Ordinary tax limitation is measured from the end of the payment-deadline year, but suspension, interruption and later loss deductions can require longer retention. Do not discard the original-loss proof merely because five years have passed since the loss year.

Report the result whenever the filing obligation applies, including a small loss. Decide whether you need assistance from record complexity and your ability to reconcile the return, rather than an invented loss threshold. Keep original-loss amounts and deductions in a ledger.

A hypothetical 2025 model has PLN 8,000 eligible income, an unused PLN 6,000 loss from 2020 and an unused PLN 12,000 loss from 2024. Assume a permitted one-off route remains available for each, with no other restrictions. Deducting the older PLN 6,000 and PLN 2,000 of the newer loss gives zero basic tax and leaves PLN 10,000 of the 2024 loss. Deducting only PLN 8,000 of the newer loss also gives zero current tax, but leaves PLN 4,000 while the 2020 loss’s window ends in 2025. The extra PLN 6,000 preserved is not a guaranteed PLN 1,140 future refund; that effect would require sufficient future eligible income and valid deductions. Correction does not restart either window.

What if you forgot to report a loss in a prior year

First check whether any original return was filed, including automatic acceptance. A missing return generally calls for a late original filing; an already filed return with omitted data calls for a permitted correction. Check applicable time limits and whether a right to correct is suspended. Address any fiscal-penal implications separately.

No tax due does not by itself eliminate a filing obligation or every potential fiscal-penal consequence. Establish whether the return is late or requires correction, and whether voluntary disclosure or another provision is relevant on the actual facts. A successful correction does not extend the five-year loss-use window.

Common mistakes and interpretive traps

Check the following distinctions when reconciling a Polish loss; no ranking of their frequency is established here.

• Mixing sources. Assess the instrument and income category before offsetting: eligible Article 30b(1) items are not all “capital income”. The private-loss model does not determine a company’s source classification or treatment of a business hedge. The forex as a company article covers that separate comparison.
• Counting the cap against the balance, not the original amount. The fifty-percent ceiling refers to the same number every year — the loss as originally reported. Two partial deductions do not shrink the ceiling.
• Overlooking the one-off route. For eligible losses incurred from 2019, assess the statutory one-off deduction of up to PLN 5 million in one of the five following years. It still requires enough qualifying income, unused loss and compliance with the other conditions; a positive year does not guarantee full use.
• Reconcile foreign-account costs. Check commissions, financing charges and fees for eligibility, documentation and correct treatment; account debiting alone does not prove deductibility. Avoid counting spread twice when it is already reflected in execution prices.
• No PIT-8C does not remove the filing obligation. Keep statements, transaction records, conversion calculations and supporting documents sufficient to establish revenue and eligible costs. An annual platform report alone is not guaranteed to prove every relevant fact.

What to do tomorrow

1. Log into your broker's portal and download annual transaction statements for the last five years — this is the foundation for checking whether any closed year was a loss you never declared. Without these statements, no honest calculation of what is still available to deduct is possible.
2. Review each filed PIT-38 using its correct yearly version. Record original Article 30b(1) losses, prior deductions, remaining balances and usable years. In the 2025 version those losses are in Part C and prior-year deductions in Part D, rather than the virtual-currency Part E.
3. Compare permissible deductions by original loss year and expiry, rather than assuming waiting for a larger gain improves relief. In the basic fixed-19% model, each eligible PLN 1 deducted has the same PLN 0.19 effect while sufficient income exists. Future income is uncertain and a year without income still uses the deduction window.
4. If a prior loss was omitted, establish whether you need a late original return or a permitted correction. Check time limits, supporting records and any fiscal-penal procedure with a qualified adviser. Do not treat voluntary disclosure and correction as interchangeable formalities.
5. Request professional assistance when income classification, incomplete records, several entities or cross-border facts make the calculation uncertain. Obtain a written fee and scope; no universal price or loss threshold establishes when advice is needed.