Hello there Anonyme,

I'm joining this thread to share some insights about this invoice customization concern.

QuickBooks Online uses the same template for all online invoices. If you want to change your invoice messages in the Company settings. Here's how:

1. Click on the Gear icon and choose Account and Settings.
2. Go to the Sales menu, then click on Messages.
3. There you can update the content of the email.
4. You can also go to the Online delivery section to update the email options of your invoices.

Visit us again if you have other questions or concerns about this topic. I'll be right here to help.