I appreciate you providing detailed information, Cassie, and for confirming that the correct GST business number is listed in your invoice template.
Yes, the new invoice layout has several changes to make things easier. One key update is the new Manage settings, which gives you control over which fields appear on your invoices.

The updated layout uses the Modern template. However, rest assured that all the information you entered in the default template, including your business number, will still be visible when you print invoices with this new design.
Since you mentioned that the old business number appears on the printed invoice instead of the updated one, I recommend contacting our live support.
Although I'd like to assist you directly, our live experts are well-equipped to dig deeper into this case and ensure that the printed invoices reflect the correct information.
Here's how you can get in touch with our live experts:
- Hover over the Help icon, then select the Search tab.
- Click Contact Us.
- In the box provided, please share your concerns regarding the new invoice layout. Specifically, describe how the printed version displays the old GST business number instead of the updated one.
- Hit Continue, and choose the Callback option.
For successful communication, please refer to this article for our support hours: Get Help with QuickBooks Products and Services.
We're always available to assist you if you have any additional questions or concerns.