Thanks for joining the thread, @Andrew93.

I can help delete the payments in QuickBooks Online (QBO).

Here's how:

1. Go to the Sales menu.
2. Click Customers.
3. Select the customer's name and proceed to the Transaction List tab.
4. Locate and click the payment to open it.
5. Click the More option at the bottom and choose Delete.
6. Select Yes to complete the process.

I've also added this article about deleting transactions in QBO: Void or delete transactions.

Get back to us if you have other questions. We're happy to help you more. Take care!