HiI have just started on QB and uploaded a csv file for bank transactions ytd, but they seem to have duplicated.What can I do?Thanks

I'll share some guidelines to help you handle these duplicated transactions.

You can exclude the transaction in the Bank Transactions section. Here is how:

1. Go to Transactions, then select Bank Transactions.
2. Select the For Review tab.
3. Choose the checkbox of the transactions to exclude.
4. Click Exclude.

Another way around this is by matching them:

1. Locate the downloaded transaction to expand the view.
2. Click on Find Match. 
3. Review the matching records found in QuickBooks. 
4. Follow the onscreen instructions to complete.

I'm also adding these articles you can use in the future:

• Categorise and match online bank transactions in QuickBooks Online.
• Reconcile an account in QuickBooks Online.

The Community always welcomes you for further inquiries about transactions. Have a great day ahead!