My client says the online QB invoice is not secure, missing https: missing the (s). How can i address his concerns?

Welcome to the QuickBooks Community, debora5.

Please note that when you send an invoice to your customer, you can advise them to double-click the URL to ensure the completed https: shows on their end. Let me provide insights on how sending emails works in QuickBooks and ensure your clients receive legitimate invoices to avoid scams.

We provide services that enhance your QuickBooks Online experience. Each of our services has its email address. All official Intuit websites end in *intuit.com. This means that when your client receives the invoice email, it contains quickbooks@notification.intuit.com. This ensures that the email received was processed and validated by Intuit. 

In addition, your client also needs to add quickbooks@notification.intuit.com email address as a "safe sender" on their email account. This is to make sure that they’re staying informed and to prevent getting any suspicious or fraudulent emails.

In case you need to view the possible reasons why might customers not receive your invoices and how to fix them, you can read this article: Troubleshoot if customers aren't receiving emails from QuickBooks Online.

Feel free to comment down below if you have any other concerns or questions about managing the client's invoice in QBO. I'm always glad to help in any way I can, debora5. Stay safe!