Hi there, lamico.

Allow me to provide some information about restoring invoice format in QuickBooks Online.

Currently, the option to restore invoice format isn't available in QuickBooks Online. As a workaround, you can manually update or add specific info to your sales form.  

Here's how:

1. Click the Gear icon in the upper-right corner.
2. Select Customer form styles under Your Company.
3. Choose a template and press Edit.
4. Go to the Content tab, then click the Pencil icon at the bottom.
5. Create a new invoice.
6. Press the Customize option at the bottom.
7. Choose the correct template.

For more information, as well as how to personalize your email message in QuickBooks, I recommend the following article: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Also, if you have customers you invoiced regularly, you may consider reading this article to help you set up recurring invoices that can be sent automatically to them: How to create a recurring invoice and manage recurring transactions. 

Please let me know if I can be of additional assistance or should you have any follow-up questions about creating templates in QBO. I’ll be here to help. Have a good one.