QuickBooks doesn't provide an option to reconnect a sales order to an already existing invoice, @bbutler1.

Let me share some information about linking sales order to invoice in QuickBooks Desktop.

You can delete the invoice and connect the sales order again. Then modify the invoice to ensure your customer doesn't get charged twice. Once you have collected payment for each item on the invoice, the item gets marked as closed on the sales order. Deleting the invoice connected to the sales order allows you to reset these checkboxes to precisely track your income.

Here’s how:

1. From the Customers menu, go to the Customer Center.
2. Select the customer's name from the Customer & Jobs list.
3. Click the Show drop-down and click Invoice.
4. Click the Edit menu and select Delete Invoice.
5. Click the Transactions tab and select Sales Orders.
6. Choose the sales order you want to connect to an invoice from the list and open it.
7. Select the option to create an invoice for all sales orders to add everything to the invoice. Modify the invoice as necessary.
8. Click Save & Close.

However, if these are only line items, it can’t be tag as close. You’ll need to copy the line items then zero out the amount to the invoice.  This way, each item on the event will be zero.

I have here an article that has detailed instructions on how to create an invoice for sales orders. You check it to learn more.

You can also visit this link for extra knowledge on how to track customer transactions in QBDT. It helps you organize your cash flow, receivables and income properly.

Don’t hesitate to visit us again in case you have other questions about QuickBooks. We’re here to answer them for you.