Hi Huffy,
Thank you for your post, and welcome to the Community Forum!
I understand that you're experiencing an issue with your activity statement displaying an old trading name instead of your current registered business name. This seems to be an unusual situation, especially since you've confirmed that your current business name is correctly set in MYOB Business Light and the changes are reflected in the ABN Lookup.
I would recommend changing the details in your BAS settings and checking your payroll business name under ATO settings.
Feel free to create a new post again if you need further assistance.
If my response has answered your inquiry, please click "Accept as Solution" to help other users find this information.
Cheers,
Princess