Cash account : The payment will be done through the Automatic Transfer system(ATS) of the bank. Brokerage will send settlement amount in the debiting/crediting of customer’s bank account 3 business days after the trading day (T+3).
Answer your question is customers don’t pay by themselves because brokerage will send data amount receive/paid to bank for automatic transfer system(ATS)
Cash balance account : A deposit is required before trading. Once customer deposit is posted to brokerage account, the funds are available for trading. The ceiling amount of which will be permitted for trade is in accordance to the amount of funds deposited. Customers who would like to open this type of account will receive an interest rate of something% per annum after netting 15% withholding tax on cash balances accordingly. The interest will be calculated and paid on a monthly basis