How do I fix NETFILE error code 21?
If you get NETFILE error code 21, it means the CRA can't accept your return because your NETFILE Access code doesn't match their records. Compare what you entered in TurboTax with the access code shown on your last year's CRA Notice of Assessment (NOA).
Here's how to review your return:
TurboTax Online
From 2025 tax return in the left menu, select Review, then Start/Continue.
Continue through the Review section.
On the Verification of personal information screen, under NETFILE Access code, make sure that the code matches the code on the NOA.
Note: The NETFILE Access code isn't a requirement for using NETFILE. The CRA’s intent with this code is to make it easier for you to prove who you are when calling them about your account.
TurboTax Desktop
From the left menu, select Introduction, then Contact info.
In the Additional Personal Information section, locate NETFILE Access Code.
Make sure that the code matches the code on the NOA.
Note: The NETFILE Access code isn't a requirement for using NETFILE. The CRA’s intent with this code is to make it easier for you to prove who you are when calling them about your account.
If you're entering the correct number, or you don't have an access code or copy of your Notice of Assessment, contact the CRA at 1-800-959-8281 for assistance.
