Yes.  You can link your existing Macquarie CMA to your ThinkTrader Share trading account. You must complete the Macquarie Third party authority form which can be downloaded here and email the completed form to transact@macquarie.com  Please also complete and sign the direct debit authority form here and return to support@thinkmarkets.com together with a copy of the completed Macquarie third party authority form.  Our support team will email you once your Macquarie CMA is linked and your ThinkTrader account is ready to go.