I see the benefits of tracking invoice activity, including its status and whether the customer has viewed it, c.lear. I'm here to guide you on how to access it.
QuickBooks Online has updated the way it displays invoice statuses. You can verify this by following these steps.
From the left navigation panel, select Sales.
Select Invoices, then click the invoice transaction to view activity history.
Furthermore, If you've received a payment from your customer, you can record it in QuickBooks to mark the invoices as paid.
You can reach out to me again if you need further assistance and clarification regarding your invoice activity. Use the reply button to submit your response.