I know that OR creates a new invoice for new bookings, and that this goes to QBO.
If I choose to sync older invoices, OR still creates a new invoice and payment that syncs to QBO. Problem is, I already have that old invoice and payment in QBO. So if I want the sync on old data, I have to delete an old invoice and payment, which is a hassle.
Is there any way to map the newly created OR invoice to my existing QBO invoice?
Unfortunately, no, there isn't a way to map to an existing invoice. This is a limitation/known flaw in how the current QB sync process works, and it is the source of duplicate invoices at times. You have to clean out anything old and let OwnerRez control creating the invoice/payment so that it knows which ones it is responsible for and can delete/update those ones in the future when it updates the same booking. It doesn't have a way to "attach" the booking to an existing/old invoice that's already in there.
Thanks for the reply.