Error: CMN.ATO.GEN.DUPLICATE.ENTRY
Answer: This is ATO side validation. Learn more
Cases:
- If the form shows as Lodged via ATO
- Form is not "Lodged" via ATO
- Future Forms
- If you need to create an Amendment
- Resolving ATO Form Cancellation Issues
If the form shows as Lodged via ATO
Please kindly check if you can see the form is lodged on ATO portal, if yes, kindly mark the form as lodged in LodgeiT.
Guide: How to "mark form as lodged"
This error triggers when the ATO rejects the return due to a return already lodged for a particular year for the TFN. In this case, please check the ATO portal to see if a return for the same year was lodge.
Form is not "Lodged" via ATO
Please try to remove the ABN from the return and attempt to lodge again. If you have attempted to relodge and still receive the error, please call the ATO, that is the fastest way and they can fix such issues online. If it didn't help - please let us know and we'll contact ATO tech team for them to investigate. Note that, it will take a week for them to response. ATO phone 13 72 86 Fast Key Code 3 1 2.
Future Forms
For 'future forms', refer to ATO's instruction Here
Before that, make sure to "Unlock" the form first, scroll through the bottom page of the form.
Then re-open the form and make sure there is no ABN on form, then try to lodge again.
If you need to create an Amendment
Open the form you're and click 'Complete' in the bottom of page

Guide: How to "mark form as lodged"

Resolving ATO Form Cancellation Issues
If you've requested the ATO to cancel the initial submission, but the form still appears as 'not-lodged' or 'cancelled' due to ATO system delays, this may trigger an error.
In such cases, we recommend contacting the ATO directly by phone for further guidance. They may advise you to proceed by lodging an amendment, which often resolves the issue.
If lodging the amendment does not work, please inform us. We can then escalate the matter to the ATO technical team for investigation. However, please note that this process may take 2–4 weeks.
Other Related Guide:
FAQ: What will you do if you in case you have lodged a tax form with wrong taxable period?