@asknbadham
Your NETFILE Access code is made up of 8 numbers and letters. Please double check that you have entered the full code and that it matches what’s on your Notice of Assessment for the last tax year.
Since the code is not mandatory, you can also try filing your return without the code.
You can get back to the page with your NETFILE Access code by clicking on “My Info”, then “[Your Name]’s Personal Information”. Then scroll to the middle of the page to find the code entry box.