LodgeiT can pull "New" and "Lodged" Activity Statement from the ATO, if you want to amend and make a change, please follow below:
1. Import the Activity statement, learn more
This example shows the difference between form that has been lodged using LodgeiT and pulled from the ATO -
2. Once the form is in LodgeiT, you need scroll through the form and press "Amend"
Once you've selected Amend, then be sure to use the Prefill option on the top Right of the form.


The status should now look like this

Error: CMN.ATO.AS.EM024

Answer:
In cases when the user creates an amendment and receive such an error on prelodge/lodge, the user must contact ATO directly. It seems ATO blocking amendment of the BAS for some reason.
ATO doesn't provide any details why the error occurs. It is possible that the issue originated from the original lodgement and this can occur for few reasons. Due to privacy reasons we are unable to elaborate further on client accounts. Can we please request agent try via online services for agents and advise the outcome. ATO suggest to use ATO portal in such cases.
We can suggest following:
1. Please try to call ATO, probably there is something on ATO why the amendment cannot be made.
2. If your client prefers LodgeiT, we can manually set the status for this form as "Completed" via backend so you will be able to sent the e-sign request to client. Once client will sign it you can amend it using ATO portal.