In a submission to the Senate Economics Committee, Acorns said CBA recently told customers that using the Acorns app increased the risk of fraud on their accounts.
“This is misleading and is not supported by the evidence,” Acorns said.
The submission also accused CBA of blocking Acorns from accessing customer data.
“Acorns has permission from Acorns’ customer to access their own data through CBA’s online bank. When this data access is blocked, it prevents CBA account-holders from fully utilising the Acorns app and service,” the submission said.
“Acorns believes that CBA was attempting to hinder and prevent Acorns from competing in the market. Acorns believes that CBA’s action is anti-competitive and likely to constitute a misuse of market power by CBA.”
In response, CBA said it “totally refutes” the allegation it is abusing market power.
The bank said it is working co-operatively with a range of third-party operators in the fintech sector and its main concern is around customer security.
“Commonwealth Bank will continue to take steps to protect customers against operational models that create a security risk,” CBA said in a statement.
“Specifically, on screen-scraping, which requires customers to disclose their online banking log-in and password credentials, creates potential security risks which have been confirmed by independent security experts.”
CBA added that it allows customers to access data in their online banking account by downloading it in a CSV file.
“This is a service that is regularly used by customers and allows easy access to data without requiring them to disclose their online banking login and password to a third party.”
In June 2016, ASIC responded to some of Acorns' concerns and conceded that some bank messaging may be outdated.