The ATO can only retrieve data when the Machine Credentials match the agent and client details.
Check the following points:
An incorrect Tax Agent is currently assigned to the client in the Client Console
The Tax Agent’s ABN does not match with the ATO Portal.
The M2M used during retrieval is incorrect.
The Profile set for the M2M is incorrect.
The credentials are not authorised to perform the action.
Remove any spaces or invalid characters from the ABN.
Confirm the M2M is valid.
If all causes listed above have been checked and the issue persists, contact the ATO.
For more information, please refer to the link below:
ato.gov.au - Access Manager Permissions for ATO and ABR Online Services