In this article
After this article, you can
- Calculate conversions with different exchange rates and fee bases.
- Separate exchange-rate effects from collected commissions.
Terms at hand: Base currency · Commission · quote currency (counter currency) · Position notional (notional value) · Balance · CFD (contract for difference)
In a hypothetical long EUR/USD trade, a 100,000-EUR lot opened at 1.0850 and closed at 1.0900 gains 50 pips, or USD 500 before costs. How that result reaches the account depends on its settlement and conversion rules. Compare the amounts actually exchanged, the tariff and the eventual withdrawal route; a foreign-currency account does not automatically remove every conversion.
How an account in your home currency works
Start with the currency of funding, the account’s reporting currency, each product’s settlement currency and the target withdrawal currency. These can differ. For a hypothetical single-currency account settling a EUR/USD CFD result into its home currency, the flow might be:
- The account is denominated in the selected home currency; funding follows the permitted route.
- You open one lot of EUR/USD, a position with a notional value of 100,000 EUR.
- Margin is calculated under the product’s rules and reported or reserved in the relevant account currency; inspect the conversion method.
- For this EUR/USD example, the price result is in USD. The account rules determine whether it stays in USD or is converted and at which executable rate and charge.
Conversion can affect realised results and separately posted charges. Whether conversion occurs, its base, timing and fee depend on the account and product. Read the actual tariff and statement rather than assuming a market-wide markup range.
Two conversions have different fee bases
Fees need not have the same amount even when both rates are 1%. An exchange-rate change and the earlier deduction change the second base.
The fictional tariff charges 1% before the first conversion and 1% after the second, in PLN. Execution rates are 4.00 and 4.40 PLN per USD. There are no instrument trades, other fees or tax; these amounts do not describe a broker's offer. The document MiFID II, Article 24 — costs and charges confirms the requirement to disclose the aggregate effect of costs; it does not prescribe this fictional deduction sequence.
The exchange-rate change increased value here, but could work in the opposite direction. A different commission timing produces a different calculation. Write down the sequence of deductions and conversions; adding 1% + 1% of the original thousand does not reproduce these flows.
What the conversion actually costs
Compare total conversion charges with your account capital and the alternative funding costs. Trade count alone does not determine the percentage: settlement amounts, gains and losses, currencies and each charge’s base matter.
What a foreign-currency account demands in return
- Any entry threshold — check the minimum funding requirement for the particular currency and account; a foreign-currency balance does not imply a common USD or EUR threshold.
- Funding currency and route — confirm accepted transfer or payment methods, sender-name requirements and any conversion or intermediary fees for the actual entity.
- Withdrawal currency and route — verify permitted destinations and whether the provider or receiving institution converts the payment. A foreign-currency bank account is not a universal prerequisite for every withdrawal method.
- Tax residence and instrument — Poland’s PIT-38 guidance covers qualifying derivative income and PLN conversion of relevant foreign-currency amounts. It is a national example: tax rules do not follow the currency you use for daily spending, and not every FX-related receipt has the same classification.
Separate conversion fees from currency valuation. Hypothetical USD 1,000 held without trades or charges is PLN 4,000 at USD/PLN 4.00 and PLN 3,600 at 3.60. The USD balance is unchanged, while its PLN value falls by PLN 400. A fee-free conversion does not remove that exposure. A home-currency balance is stable in nominal units, not necessarily in purchasing power.
Holding an existing foreign-currency saving does not make additional currency exposure neutral. Assess the combined balance and liabilities in the currency relevant to the decision. Compare this valuation effect separately from fees; neither a prior USD holding nor a large trade count determines the right account format.
Making the decision
- Small conversion flows — compare the actual fee with funding and withdrawal costs before changing currency.
- Frequent settlements — calculate each charged conversion base rather than using trade count as a decision threshold.
- Large conversion flows — check both total fees and the extra currency exposure of a foreign-currency balance.
- Long-term investing — consider asset currency, funding needs and the currency in which you measure the portfolio.
- Instruments settled in several currencies — distinguish separate accounts, currency subaccounts and a single multi-currency ledger. Available balances and automatic conversion rules depend on the provider and entity.
Find the conversion method and fee in the effective account tariff. Reconstruct the amounts actually converted, compare the full alternative funding route and consider the currency risk of idle funds. No fixed percentage of capital decides the choice for every account.
Opening a foreign-currency account at a bank
Check the receiving account or payment method before requesting a USD or EUR withdrawal. Confirm ownership, supported currencies, intermediary charges and the conversion rate if the incoming currency differs. Those terms are specific to the institutions and route.
- Confirm that the intended account or payment route accepts the currency.
- Check eligibility, verification and processing steps; no universal opening time is established here.
- Read any maintenance or minimum-balance charges.
- Check receiving and intermediary fees for the particular incoming transfer.
- Check outgoing fees and whether the quoted amount includes every intermediary.
If you ultimately need home currency, compare the amount delivered after all fees at an executable rate through the permitted routes. Revolut or Wise is not automatically cheaper or an accepted broker-payment method. See how to deposit and withdraw money at a broker, currency exchange versus forex broker and CRS and FATCA and whether a foreign broker reports your account for the distinct payment, product and reporting questions.
What to do tomorrow
- Read the actual conversion formula. Record the reference/executable rate, markup or commission, charged base, minimum and timing. A bare percentage does not reconstruct a conversion.
- Reconstruct the charged conversion bases. Export the individual conversions and charges, including their currency and direction. Do not simply sum signed gains, losses, commissions and swaps: cancellation in that sum may conceal conversions on which fees were actually collected.
- Compare complete cash flows. Include funding, withdrawal, account maintenance and conversion costs. A minimum deposit is capital, not a fee to add as an expense. In a hypothetical PLN model, separate conversions of USD 1,000 profit and USD 900 loss at 4 PLN/USD with a 0.5% fee cost PLN 20 + PLN 18 = PLN 38; converting only the USD 100 net costs PLN 2 if the account permits it. The post-fee results are PLN 362 and PLN 398, with other costs and tax excluded.
Check your understanding
One short exercise
About 2 min · you can try again
What amount is the second 1% fee based on in the diagram?
- The original 1,000 PLN: 10 PLN.
- 247.50 USD, calling the result PLN.
- 1,089 PLN: 10.89 PLN.
Check the answer and explanation
1,089 PLN: 10.89 PLN.
247.50 USD × 4.40 gives the second PLN base.
Frequently asked
How big are real conversion costs?
Use the actual tariff and conversion base. In a hypothetical 1% charge on a USD 500 conversion, the fee is USD 5; 100 such separately charged conversions cost USD 500 before other costs. This is not a market-wide rate. Do not assume that notional, price result, commission and funding all use the same conversion rule.
How to deposit in foreign currency?
Check the permitted methods for the entity and account, supported currencies and ownership requirements. Compare the amount delivered after sender, intermediary, receiving and conversion charges. A named payment service or card is not universally accepted, fastest or cheapest; the source of funds and payment route must match the provider’s rules.
Can I have accounts in multiple currencies?
Some services provide separate accounts or subaccounts; others hold several currency balances in one ledger. IBKR’s base currency is used for reporting and margin calculations and changing it does not by itself exchange existing cash. Check available balances, actual conversion and margin rules; multiple currencies do not guarantee no fees or independent margin pools.
Does the account currency change my tax bill?
Account denomination does not remove tax reporting obligations, but tax treatment and conversion rules depend on residence and instrument. For the Polish CFD example, check the applicable PLN conversion dates and statements rather than assuming a foreign-currency account eliminates conversion. PIT-38, PIT-8C and NBP rates are national references; use the authority and rules relevant to your own tax residence.
Sources & bibliography
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XTB Forex products and accounts · XTB’s Polish-language information about its Forex offering. www.xtb.com ↗
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IC Markets Raw Spread Account — multi-currency setup · IC Markets’ description of the Raw Spread account and its account settings. www.icmarkets.com ↗
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Wise Multi-currency account (UK) · Wise’s UK multi-currency-account product information. wise.com ↗
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ESMA MiFID II — Article 24: general principles and information to clients · The EU provisions require comprehensible aggregate cost information; they do not prescribe the hypothetical conversion formula used here. www.esma.europa.eu ↗
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Interactive Brokers Base Currency · The provider distinguishes reporting and margin base currency from actual currency balances and exchange operations. gdcdyn.interactivebrokers.com ↗
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Polish Ministry of Finance PIT-38 information booklet for 2025 · The Polish tax-year guide covers qualifying instruments and foreign-currency reporting; spending or account currency does not create a worldwide tax rule. www.podatki.gov.pl ↗
