You've done nothing wrong, @sanpran.
Since the invoices are unpaid even with the correct format after importing the IIF file, I'd recommend contacting our Customer Care Support. Someone can help you reformat your IIF file of the invoice so you can import it with the correct status under the PAID column.
- Go to Help.
- Select QuickBooks Desktop Help.
- Click Contact Us.
Lastly, here's a few articles you can read to learn more about how you can manage your account and related transactions: Help Articles for QuickBooks Desktop.
If there's anything else that I can help you with, let me know in the comments. I'll be here to lend a hand.
