Hello, @wrmcm. 

If you’ll going to update a payment or sales receipt that has been deposited, you’ll need to remove it from the deposit. 

You can do it from the Chart of Accounts from the Gear icon. Find the account and select View register. This will let you view all the sales receipts and payments connected to the deposit.

From here remove the checkmark from the incorrect payment or sales receipt. This will remove the transactions from the deposit.

You can identify if the transaction was already reconciled if it has the letter R in the Reconciliation box before making changes. Make sure you add it back in order not to encounter any errors the next time you reconcile. 

Check the following article for more information: How to edit a payment or sales receipt that has been deposited. 

Let me know if you still have any questions. I'm always here to assist. Have a wonderful day!