Invoice processing

You can utilize the Receive Payment feature in QuickBooks Online (QBO) to send invoice payment receipt, @Aaron731. Let me provide the step by step process.

This process also ensure that you recorded the payment in QuickBooks to mark the invoice as paid.

Here's how:
 

1. Click the +New icon and select Receive payment.
   
2. Choose the customer in the Customer drop-arrow.
3. Tick the boxes for the invoice you want to tag as received payment.
4. Select Save and send.
   
5. Provide the email address and click Send and close.
   
    

On the other hand, you can also receive the payment from the Invoices page. Just click Receive payment next to the invoice you want to receive payment into. Enter the necessary details and click Save and send. Then, provide the email address and click Send and close.



Additionally, please make sure that you've ticked the PDF Attached option in the Account and Settings. To ensure the payment receipt is attached to the email. I'll show you how.
 

1. Go to the Gear icon.
2. Select the Account and Settings.
3. From the Sales tab, scroll down and click the Edit icon in the Online delivery section.
4. Ticked the Show full details in email and PDF Attached.
5. Click Save and Done.
    

You can check out this article for more details in managing invoice payments: Record invoice payments in QuickBooks Online.

Furthermore, let me share this article for future reference in case you need to record a refund to your customer: Record a customer refund in QuickBooks Online.

Feel fee to tag me in this thread if you have clarification or questions about receiving payments from your customer. I'm always around to help you.