The platform, called iShop, bundles CBA's eVolve payment gateway with a suite of internally-developed software that enables customers to set up a customisable online shop front.
CBA will host the service internally, according to general manager of merchant services, Dominic White.
Credit card numbers are held securely by the bank, he said.
"The temptation for financial institutions tends to be to white label existing [e-commerce] packages from various service providers," White said.
"Commonwealth Bank eVolve moves away from this model.
"We have listened to what our customers have told us is important to them, and following a successful pilot with a group of the Bank's business customers in February 2009, we believe the functionality of Commonwealth Bank eVolve meets these needs."
Further comment is being sought from the bank on the development of the platform.
CBA's decision to launch an e-commerce platform and hosted payment gateway comes after a spate of incidents that compromised the card details of customers.
CBA will be hoping it can instill or restore trust in retail SMB and SME e-commerce sites by enabling them to leverage off the bank's own infrastructure.
Using iShop, business owners are able to design, implement and manage their own online shop fronts
"It can be as simple as uploading and entering product details and selecting a design template for their shopping cart," CBA said.