Hello there, @Anonymous.

Please allow me to join the thread and help share a little more information about adding variables on invoices.

You have the option to customize your template as mentioned by my colleague HoneyLynn_G above, since this feature isn't available in QuickBooks Online (QBO) as of the moment.

On the other hand, I'll take note with this, so I'll be able to pass along the suggestions for you, so you'll be able to use this feature in QBO as quickly as possible.

For you to stay updated with the latest QuickBooks news and updates, you may visit our QuickBooks blog: https://quickbooks.intuit.com/blog/.

Please feel free to visit us here on the Community page if you have any other invoices concerns, I'll be always here to help you. Have a great day ahead!