How to reverse the entry to Uncategorized Income?

Hi there, AndyHowell.

I'll help with your question about reversing the category that was assigned to a banking transaction. Can you also tell us if the transaction was downloaded through Online Banking? If so, follow these steps on how to use the Undo feature:

1. Go to the Banking menu and select the Banking tab.
2. Look for the transaction under the Categorized tab. 
3. Click the Undo button under the Action column.

After clicking Undo, the transaction will go back to the For Review tab. Then, you can match it to the existing invoice to close it out. Follow the steps in this article for more details: Categorize And Match Online Bank Transactions In QuickBooks Online.

Let me know if you need anything else. 

That did the trick.  I found some other mistaken one didn't know about as well. Thanks!