Good to see you, ben48.
In QuickBooks Online, we can apply retention to an invoice by creating a retainage item and retainage receivable account as its income account. Then, manually add it on the invoice as another line item.
With regards to your concern, we can just remove or don't add the retainage item into the invoice. That way, QuickBooks won't calculate the retention.
Below are some of the articles about invoices:
I'll be right here if you have more questions. Have a great day!
