You need to reverse the deal by booking an opposite deal through FXOnline. Please indicate "towards reversal of Deal ticket number XXXX " in the memo field. E.g. If you have entered a Sell USD deal for $20,000 instead of a Buy USD deal, first you have to cancel the original contract by booking a Buy USD deal for the same amount and then book the correct deal. As per Reserve Bank of India guidelines if the reversal results in a profit, it will not be passed on to the client. If the reversal results in a loss, it has to be borne by the client.