We only charge commissions when you trade FX on a Commission Account or an STP Pro Account. Commission Accounts trade on low variable spreads plus a flat $5 commission per standard lot (100K) that is charged at the time the trade is executed. STP Pro Accounts have variable commissions based on volume traded.
For example, if you bought 200,000 EUR/USD with a 0.2 spread on your Commission Account, you would be charged $10 in commission plus a spread cost of $2. If you then sold the 200,000 EUR/USD with the same 0.2 spread, you would be charged $10 in commission plus the spread cost of $2. If you only sold 50,000 of your position, you would be charged $2.50 in commission with a spread cost of 50 cents.
If you have a Standard Account, your pricing is spread-only and you will not be charged commissions at all. Click here to learn more.