Please try submitting your return without the NETFILE Access Code (NAC). The NAC is optional and not required to file your return.
If this doesn’t solve the problem, please contact us by phone for more assistance. To talk to our phone support team, visit https://support.turbotax.intuit.ca/contact/. After entering some basic info about what you need help with, the page will give you the phone number for the team best suited to help.