I've got some information to share regarding invoices in QuickBooks Online (QBO), hltay.
Marking your invoice as pending is currently unavailable in QBO. As you create your invoice transaction, these are the following statuses that are available and their meanings:
Open -You haven’t emailed the invoice yet.
Open (Sent) - You already emailed the invoice to the customer.
Open (Viewed) - Your customer opened the invoice.
Paid - Your customer paid the invoice.
Overdue -The invoice is past due and hasn’t been paid yet.
Overdue (Viewed) -Your customer opened but didn’t pay the past-due invoice.
As a result, I recommend sending feedback to our developer team for them to analyze and may include this feature in future releases.
Go to the Gear icon located in your top right corner.