After categorizing an expense we find it is duplicated with a transaction that is already in the register. What are we doing wrong?

Hello, @Library02655. I'm here to help you remove a categorized duplicate transaction.

Duplicate transactions can occur when downloaded transactions fail to match and transfers are added twice. Furthermore, since each bank connects to QuickBooks (QB) differently, there can be crossed wires.

To remove the duplicate transaction, you can exclude it. This way, it won't show up in any account registers or financial reports. 

Here's how:

1. Go to Transactions, then choose Bank transactions.
2. Open the Categorized tab and look for the duplicate transaction.
3. Under the Action column, click Undo. This will move the transaction to the For Review tab.
4. Head to the For Review tab and select the checkbox of the transaction to exclude.
5. Click Exclude. This will transfer the transaction to the Excluded tab of the banking page.

For more detailed information, you can visit this article: Exclude a bank transaction you downloaded into QuickBooks Online.

In case you want to automatically categorize transactions from your bank, you can check out this article for more guidance: Set up bank rules to categorize online banking transactions in QuickBooks Online.

Feel at ease to share any questions besides removing a categorized duplicate transaction. I'll be a message away to help you. Have a good one!