I frequently use invoices that are paid partially. How do I display the "amount received" to my clients so that they see that the proper amount has been deducted?

Thank you for visiting the Community, @Stewart Engr. 

I can help share a method to let your client see their invoice payment or the "amount received". 

Currently, the option to add the amount received in an invoice template is unavailable. For now, you can use the statement to let your client know about their payments.

I recommend using the Transaction Statement type which is the closest option to the information you need. It shows the actual invoice of the customer and the amount received when it was paid. Let me guide you how: 

1. At the top right, click the Plus icon.  
2. Select Statement.
3. From the Create Statement page, select Transaction Statement in the drop-down list.
4. Filter the Start and End Date.
5. Click Apply.
6. Click the Statements available tab.
7. Select the customer's name.
8. Click Save and send. 
9. Select Send.

Also, I've got an article for you that offers some pointers on creating and managing statements in QuickBooks Online: How to create and manage statements.

I appreciate you for sharing your thoughts. I'll make sure to take note of your suggestion which can be used for product future updates.

That should do it. If you have any clarifications about invoices or questions about QBO, feel free to leave a comment below. I'll be happy to help you further. Have a great day. 

A few follow up questions:

1. Should I send the statement in addition to the invoice? Or instead of the invoice?

2. Does the statement request payment from a client like an invoice does? Or is it only for information purposes and there is no way to "pay" it?

3. Does sending a statement impact my register, liabilities, taxes, or other financial tracking in Quickbooks Online in any way?