The lender assured customers there was no need to worry as the tapes did not contain passwords, PIN numbers or other data that could be used for fraudulent purposes.
This follows CBA's admission it couldn't confirm whether the tapes, which were retained so bank statement could be printed, were destroyed or not.
The bank says two magnetic tapes which contained the data were scheduled for destruction, but that the tapes can not now be accounted for.
The bank said it had confirmed there was no evidence of information being compromised for the 19.8 million accounts involved or suspicious activity following the incident.
Meanwhile, the saga has sparked renewed interest from the Office of the Australian Information Commissioner which this week contacted CBA asking for more information.
The tapes were meant to be destroyed; however, the bank admitted it had been "unable to confirm the scheduled destruction" and ordered a forensic investigation by KPMG.
Rod Rosenstein: Justice Department is 'not going to be extorted'
Rosenstein said. "The Justice Department is independent of inappropriate political considerations". But he said the DOJ's work would not be affected by threats.
Australia's largest bank fell victim to a massive financial services privacy breach in 2016 but never bothered to alert affected customers.
The bank explained that it decided not to notify customers given the results of the investigations. The probe found no evidence that customers' data had been compromised, or accessed by third parties, CBA added. We discussed this course of action with the OAIC who subsequently advised that it did not intend to take any further action in relation to the matter.
CBA's Beem instant payments platform inadvertently revealed the email addresses of thousands of customers on Tuesday at the same time as the Australian Prudential Regulation Authority released damaging findings from an independent inquiry into operational risk failures across the bank's operations.
The privacy commissioner is now asking the bank for further information about the incident.
In 2005, the Bank of America lost several tape drives as they were moved between facilities, affecting about 1.2 million U.S. federal employees.
If you're with Commonwealth Bank, sorry dude - it turns out the bank actually lost its data on 12 million customers two years ago, and didn't bother to tell you.