wrong netfile access code

[graham]

I made a mistake putting in the netfile access code. The file was rejected , number 21,

 

I cant find the place where one puts in the access code to correct it.

 

help!!

[Geo123]

Hello graham,

Error code 21 / Result code 21 : The Canada Revenue Agency was unable to accept your return, as your NETFILE Access code did not match our records. Make sure you have
Your unique Access code (8 characters)  can be found on your Notice of Assessment (NOA) for a previous tax year. This eight-character Access code is made up of numbers and letters and is located on the right side of your NOA. The placement and labelling of the Access code differs slightly depending on the version of the NOA you are looking at, but will always be on the right side of the NOA.
On the paper version of your NOA as well as the PDF version in My Account, the Access code is not labelled, but can be found directly underneath the Date issued at the top right of the page. If you are viewing your NOA in My Account or using the Express NOA service in certified tax software, the Access code is found directly under the Notice details box at the top right of the page.
OR
Call the CRA 800-959-7383
The NAC is not required to NetFile.  While this Access code is not mandatory, if you do not enter your Access code, you will not be able to use any information from your 2023 tax return when confirming your identity with the Canada Revenue Agency. You will have to rely on other information for authentication purposes.