How do I delete/void a credit card payment in QBO?

voiding the invoice is the problem, do not do that. recreate the invoice and apply the payment.

the amount you reversed should have posted to the sales income discount account which will offset the invoice posting to sales

Thanks!  Since I reversed it on the Quickbook Payments site, it will send the entry to QBO to offset?

Thanks for getting back to us and for sharing additional details, @mongercj.

The reversal you made in your QuickBooks Payment accounts will not sync to your QuickBooks Online (QBO). Thus, we'll need to manually delete the Unapplied payment to offset it. Let me show you how.

1. Go to the Sales menu.
2. Select the Customers tab.
3. Locate and select your preferred customer.
4. Go to the Transaction List tab.
5. Click the Unapplied payment.
6. Select Clear Payment.
7. Click More and select Delete.
8. Then Save and close.

To be guided either to delete or void transactions in your account, you can refer to this article for reference: Void or delete transactions in QuickBooks Online.

I’m also attaching this link that you can use for future guidance in matching your bank statement and QuickBooks balance: Reconcile an account in QuickBooks Online

Keep me in the loop if you need further assistance managing your transactions. I’m always around to assist you. Stay safe.

Thanks for these steps!  But I'm getting this error when I click 'Delete' in Step 7.

This transaction has been deposited. If you want to change or delete it, you must edit the deposit it appears on and remove it first.

I can share why you're getting the error when deleting the unapplied payment, mongercj.

This error indicates that you're attempting to change a total of a payment already on a deposit. You need to delete the deposit first before you can make changes to the payment.

Here's how: 

1. Click Accounting in the left navigation bar.
2. Select Chart of Accounts.
3. Look for the account and click View Register.
4. Find the payment and right-click Delete.
5. If you want to delete a specific payment, select it from the list.
6. Now click the Edit tab at the top menu bar.
7. Select Delete Line.
8. Select Yes to confirm your changes.

For further details about deposits, you can also check this article: Record and make Bank Deposits in QuickBooks Online.

Also, I'm adding our QuickBooks Online-Video Tutorials on how to create sales receipts and process payments with QuickBooks.

Stay in touch with me if you have any other questions about this by commenting below. I'll be right here to help you. Have a good one. 

That worked...thanks again!

Thank you @mongercj for coming back to the Community and letting us know this worked for you! Please don't hesitate to come back if you have any other questions. We're all very eager to help!

Have a wonderful week. :)