明智理財戶口 (SmartSavings) is an integrated account, meaning, it has savings, current, investment, foreign currency, paper gold account in one package.
if you use SmartSavings, and you would like to process the securities trading via phone service, you still need to use the SmartSaving's investment account, coz ALL the securities/stocks, they HAVE TO put it under the investment account, but you can choose to put it under the SmartSaving's investment account or the standalone investment account.
you CANNOT 設定唔用證券戶口. You can just set to a different settlement account as said, to your standalone investment account OR SmartSavings investment account.
When you process the trade order, you just need to tell the staff which investment account that you want to put to, then that's okay, you don't really need to fill form to set that.
p.s., different investment account, they have different investment order placing hotline, whichever account you want to put the stock to, then you call to the relevant hotline, number are as below: