How to get the client's invoice viewed how many times? The invoice includes all of his details like the address, phone number, and email address.

Hi, CharmCr.

I can see how important it is to check how many times your client has viewed the invoices. 

Though, we're unable to do this in QuickBooks Online. So, I recommend sending feedback to our product developers to add your vote about this feature and to help us improve our services. Here's how:
 

1. Go to the Gear icon and click Feedback.
2. Provide your feedback or product suggestions.
3. Click Next to submit.

You can refer to these links if you want to enter customer payments or personalize the sales forms:
 

• Record invoice payments in QuickBooks Online
• Customize invoices, estimates, and sales receipts in QuickBooks Online

Let us know if you have further questions about managing your invoices. I'll be glad to help you. Have a good one.