Forex tax compared — Poland versus the United Kingdom in 2026

Polish traders ask me regularly whether it pays to open an account with a British broker, because "in London spread betting is tax-free". Yes, it is — but only for a UK tax resident. A Polish resident pays in Poland even when the broker sits in the City. In this piece I lay out what the tax burden really looks like on both sides of the Channel, using concrete numbers and a worked example.

What does Poland's PIT-38 say about forex?

In Poland, the result from trading CFDs on currencies, indices and commodities lands in the same pot as dividends and share disposals. You file it on form PIT-38 by 30 April of the year after closing your positions, the rate is flat 19 percent on profit. This is the famous Belka tax — introduced in December 2001 and named after the finance minister at the time. Polish rules grant no annual exempt amount for gains from securities or derivatives: the first zloty of profit is taxed the same as the hundred thousandth.

A Polish broker issues a PIT-8C and aggregates the year's result for you. A foreign broker, such as Britain's IG or CMC Markets, will not — you must rebuild the year yourself from the annual statement and convert each trade by the average NBP exchange rate from the day before closing. For cross-border bookkeeping habits, see the practical notes in ForexMechanics on taxes and records. A loss for the year goes on the same return and offsets gains in the next five years, capped at 50 percent of the gain in any single year.

Three tax paths for a British forex trader

The United Kingdom has no single, neat way to tax currency speculation. HMRC distinguishes three paths, and the choice is not always the trader's.

The first is spread betting — a uniquely British product. You place a bet on the direction of a price (pence per point on cable or the DAX), and the profit counts as a gambling win for HMRC, not subject to income tax or capital gains tax. The exception in manual BIM22020 is important: if the bets form an integral part of a trade you are running (for example, when a bookmaker hedges client positions), HMRC may recast the proceeds as taxable income. For an ordinary retail account, spread betting stays tax-free.

The second path is CFD trading, the closest analogue to what we know from Polish accounts. The result falls under Capital Gains Tax (CGT), with an annual exempt amount of GBP 3,000 in the 2024/25 tax year (previously GBP 6,000). In the basic-rate income band the CGT rate is 10 percent, in the higher band it is 20 percent. From 6 April 2026 the rates rose to 18 and 24 percent, but I keep the worked example in the older regime so the comparison stays consistent with the UK 2024/25 tax year.

The third path appears when HMRC decides the trader is conducting a trade. The CFD result then becomes income, with rates of 20 percent in the basic band, 40 percent in the higher band and 45 percent in the additional band. The criteria are soft: regularity, organisation, livelihood, professional setup. The same risk that Polish tax offices use when treating active trading as economic activity.

"Whether or not a particular spread bet is taxable will depend on the terms of the contract and the economic substance of what is done." — HMRC, Business Income Manual BIM22020 — Spread betting, 2023.

A numeric comparison on GBP 20,000 of annual profit

Take a hypothetical trader with GBP 20,000 of annual profit — at an exchange rate of 5.00 PLN per pound, that is roughly PLN 100,000. An illustrative example, with no allowable costs and no losses carried forward.

The figures are hypothetical and do not constitute tax advice. In real life you also handle NBP conversions, any deductible costs (courses, software) and — in the United Kingdom — whether your overall income stays within the basic band capped at GBP 50,270.

Why tax residency decides where you pay

A Polish resident using a UK spread-betting broker does not inherit the British exemption. The Polish PIT Act (article 3 paragraph 1a) treats as a resident any person whose centre of vital interests sits in Poland or who spends more than 183 days a year in the country. Such a person reports all currency speculation on PIT-38, regardless of whether the account is run by a broker in Cyprus, Britain or Australia.

What is more, the Polish tax office can challenge the British classification of spread betting as gambling. If a trader follows a strategy systematically, uses a charting platform and treats the account as a source of income, the office typically reads that as a derivative — meaning PIT-38, not gambling tax. The British HMRC interpretation is irrelevant to Polish authorities.

One more thing worth remembering: the United Kingdom and Poland exchange tax data under the Common Reporting Standard (OECD). Every deposit, withdrawal and year-end balance on a British brokerage account lands once a year on the desk of the Polish National Revenue Administration. The "I will not declare it, they will not find it" approach stopped working long ago. A dispute with the office usually starts with a question about an undeclared account in a jurisdiction that has shared data with Poland for years.

What this means in practice for a Polish trader in 2026

The short answer: there is no magic shortcut. UK spread betting is a legal but local privilege of British residents. A Polish trader who genuinely wants it must move tax residency — actually live in the United Kingdom, pass the Statutory Residence Test, shift the centre of vital interests. That is a project measured in years and life decisions, not in annual tax optimisation.

For 95 percent of readers the rational route is a clean PIT-38 in Poland, possibly with a review of whether business activity is worth it (see JDG versus a Polish company) and whether trading already qualifies as professional. If you are emigrating for other reasons (family, work, education), the United Kingdom is genuinely cheaper for a CFD trader — but the move has to stand on its own merits, not on a "because taxes" argument.

What to do tomorrow

1. Verify whether you remain a Polish tax resident in 2026: count your days in Poland, locate your centre of vital interests (family, main income source, social security). If you spend more than 183 days here or keep family and work in Poland, you file forex tax in Poland — regardless of where your broker is registered.
2. Open the annual statement from your broker for 2025 and convert every closed trade by the average NBP exchange rate from the day before closing. British and Cypriot brokers do not issue PIT-8C, so you must rebuild your PIT-38 yourself. A detailed template lives in the guide capital gains tax in Poland.
3. If anyone sells you an "offshore structure" or a UK spread-betting account as an exemption from Polish tax, refuse and do not sign. For a Polish resident this is illegal tax evasion, and the tax office sees foreign brokerage transfers via the Common Reporting Standard exchange of information.
4. Before you decide to emigrate "for the tax", book a session with a tax adviser who knows both jurisdictions. The Statutory Residence Test, Poland's exit tax on residency change, social security, access to UK spread-betting brokers (some require UK residency from day one) — all of it shifts the calculation in ways you cannot work out in your head.
5. If your forex result climbs above PLN 50,000 a year and you trade daily, check whether the tax office could reclassify your activity as economic activity. A consultation with an accountant or tax adviser costs PLN 300–500 and can save you many multiples of that in a dispute. See also the comparison of tax residency for forex traders.