What paying in another currency actually costs

A bet placed in a currency you do not hold is converted twice: once when funding the account and once when withdrawing. Each conversion carries a spread — the gap between the rate you get and the rate the market is trading at — and that spread is charged whether the account wins or loses.

Conversion spread is not a fee in the sense of a line on a statement. It is embedded in the rate, which is why it is easy to miss and why two providers quoting 'no commission' can differ by several per cent. On a betting account the amount converted is not the profit but the whole turnover funded, so the cost scales with how often money moves rather than with how well the betting goes.

It does not mean a multi-currency account removes the cost. It moves the conversion to a different provider, and the question becomes which provider's spread is narrower and whether the account can be funded and paid out in the same currency it bets in.

Which is where it goes wrong. The compounding case is moving money in and out frequently. Each round trip pays the spread twice, so a habit of withdrawing small amounts weekly can cost more over a season than any single bad price.

What to do with it. Hold the account in a currency you can fund and withdraw in without conversion if that is available. If it is not, move money rarely and in larger amounts.