🧾 Introduction
The best way to pay less tax is to legally increase your Deductible Costs (Koszty Uzyskania Przychodu). Every Złoty you validly claim as a cost reduces your tax bill by 19 groszy.
However, Poland has strict rules on what counts as a "Cost". If you try to deduct your internet bill or your trading course, you might expose yourself to a fine.
This guide clarifies exactly what you CAN and CANNOT deduct in your PIT-38.
✅ YES: These Are Deductible
According to the law, a cost must be directly related to the acquisition or sale of the asset.
- Purchase Price: The amount you paid for the stock/crypto itself.
- Broker Commissions & Fees: The fee you paid to Binance, Interactive Brokers, or XTB for executing the trade.
- Exchange Spreads: If the broker builds the fee into the exchange rate (spread), this is effectively part of the purchase price (make sure you use the actual amount paid).
- Transaction Taxes: Any "Stamp Duty" or "Tobin Tax" paid on the transaction (common in UK/French markets).
❌ NO: These Are NOT Deductible
Many things that feel like "investing costs" are ignored by the tax office because they are not direct transaction costs.
- Educational Courses: Books, seminars, or "Masterclasses" on trading. (These are personal education).
- Hardware: Your laptop, ledger, or phone.
- Subscriptions: TradingView, Bloomberg Terminal, or paid Discord groups.
- Internet/Electricity: Unless you trade as a registered business (B2B), you cannot deduct these household bills.
- Wallet Transfer Fees: Gas fees paid to move crypto from Wallet A to Wallet B are usually NOT deductible, because they didn't generate income; they just moved money. (Only gas fees for swapping on DEXs are deductible).
🧮 Example: The True Cost Calculation
Let's assume you trade on a foreign platform.
- Buy: 1 Stock @ $100.
- Commission: $1.
- NBP Rate (Day before): 4.00 PLN.
- Sell: 1 Stock @ $150.
- Commission: $1.
- NBP Rate (Day before): 4.20 PLN.
1. Calculate Income (Przychód)
$$ 150 \times 4.20 = \mathbf{630 \text{ PLN}} $$ (Note: You do NOT subtract the sell commission here. Income is Gross).
2. Calculate Costs (Koszty)
- Stock Price: $100 \times 4.00 = 400 \text{ PLN}$
- Buy Commission: $1 \times 4.00 = 4 \text{ PLN}$
- Sell Commission: $1 \times 4.20 = 4.20 \text{ PLN}$
Total Deductible Costs: $400 + 4 + 4.20 = \mathbf{408.20 \text{ PLN}}$
3. Profit (Dochód)
$$ 630 - 408.20 = \mathbf{221.80 \text{ PLN}} $$
Tax (19%): $221.80 \times 0.19 = \mathbf{42 \text{ PLN}}$
🧾 How to Fill PIT-38
Include all those small commissions! They add up.
- Field 22 (Income): 630 PLN
- Field 23 (Costs): 408.20 PLN
If you had ignored the commissions, you would have declared 400 PLN costs and paid tax on 230 PLN profit. You saved money by being precise.
✅ Final Checklist
- Did you include the sell commission in your costs? (Many people forget this one).
- Did you convert fees using the historical NBP rate from the transaction day?
- Do you have a PDF confirmation for every trade in case of an audit?
Precision pays off. Don't leave money on the table, but don't invent costs that don't exist.