Thanks for reaching out to the Community, jelemoine78.
There are two simple ways to create an invoice and assign it to the customer.
You can use the Plus sign icon or go to the customers list and enter a transaction.
I'll show you how:
Another way is on the customers list. Here's how:
Check out this article for more details when adding an invoice: Create an invoice.
I also want to make sure you get the most out of QuickBooks Online, I'm including a link to some of our videotutorials: https://quickbooks.intuit.com/tutorials/.
Let me know if you have other questions. I'm here to provide the information you need. Wishing you continued success.
Hello, you can also use Business Importer app. Type your invoice data ( customer name, amount ,date, product and so on ) in Excel and then import into QBO via this app.