🧾 Introduction
When filing your PIT-38 in Poland, you are allowed to deduct certain costs related to your investments — this reduces your taxable income and lowers the 19% capital gains tax.
This guide explains in simple terms what deductible costs are, how to calculate them, and how to record them correctly in your PIT-38 form.
💡 What Are Deductible Costs?
Deductible costs are all expenses directly linked to earning your investment income.
They include, among others:
- Purchase price of shares, ETFs, or cryptocurrencies
- Transaction fees or broker commissions
- Currency conversion fees (if applicable)
- Stamp duties or similar trading-related costs
⚠️ Note: Monthly broker fees or account maintenance charges are not deductible unless they are tied directly to specific trades.
🧮 Example: Calculating Deductible Costs for Stock Transactions
Let's assume the following transactions:
| Date | Event | Amount (EUR) | Details |
|---|---|---|---|
| 1 Feb 2024 | Buy 10 shares @ €100 | €1,000 | €2 commission |
| 15 Jun 2024 | Sell 10 shares @ €120 | €1,200 | €2 commission |
Step 1: Convert to PLN Using NBP Rate
- Buy date (31 Jan 2024 rate): 4.35 PLN/EUR
- Sell date (14 Jun 2024 rate): 4.45 PLN/EUR
Step 2: Calculate Income and Cost
| Type | EUR | Rate | PLN |
|---|---|---|---|
| Sale (income) | €1,200 | 4.45 | 5,340 |
| Purchase (cost) | €1,000 | 4.35 | 4,350 |
| Commission (buy) | €2 | 4.35 | 8.70 |
| Commission (sell) | €2 | 4.45 | 8.90 |
Total Cost = 4,350 + 8.70 + 8.90 = 4,367.60 PLN
Income = 5,340 PLN
Profit = 5,340 − 4,367.60 = 972.40 PLN
Tax = 19% × 972.40 = 184.76 PLN
🧾 Declaring in PIT-38
In the PIT-38 form:
- Field 22 – Income (total from sales) = 5,340 PLN
- Field 23 – Costs (deductible) = 4,367.60 PLN
- Field 26 – Profit = 972.40 PLN
⚠️ Common Mistakes to Avoid
- ❌ Forgetting to include broker commissions.
- ❌ Using current exchange rate instead of NBP rate from the previous business day.
- ❌ Reporting income but not including related costs (overpaying tax).
✅ Final Tips
- Always record the NBP rate for each transaction date.
- Keep a clear transaction log with amounts and fees.
- Use spreadsheets to track your costs and income easily.
- Keep your broker statements as documentation for 5 years.
By declaring your deductible costs properly, you can significantly reduce your PIT-38 tax burden.