New company address but have open invoices pre-address change. We use a custom template. Is there any way to apply the new address retroactively?

Hi! @lcantees, hope you are having a good day. I can show you how to edit your previous invoices.

It's simple to add a new company address in QuickBooks Online (QBO). However, we'll have to do it manually in order to apply it to our previous invoices. 

Here’s how to do it:

1. Go to Sales and then click Customers.
2. Choose the customer that you want to edit the invoice with.
3. Select invoice and then go to the location section.
4. Enter the new business address.
5. You can repeat the process until you’ve edited all the invoices’ company address.

If you want to automatically populate email address when emailing customer invoices, you can refer to this thread.

Stay in touch with me if there's anything else you need about managing invoices. I'm always glad to help.