If forms have already been lodged under that ACN, you need to delete the company from HandiRegister to change it. Before deleting, save any documents you need. After deleting the company, re-add it with the correct ACN. You may also need to lodge Form 362 to be added as the agent.
HandiRegister - Change ACN if a Company has been Deregistered in HandiRegister
If a Company has changed their ACN and the name is the same as a company already in HandiRegister.
Updated over a month ago