Am converting from desktop to QB online. Have hundreds of transactions in bank account already. How do I connect to bank online without downloading duplicates?

Hello there, @dankeyes. I'm here to ensure you'll be able to download your bank transactions in QuickBooks Online (QBO) smoothly. 

When you connect your bank to online banking, this downloads the latest and maximum number of transactions available from it. Each financial institution is linked differently and sometimes there are cross wires. That said, QBO might download duplicate transactions occasionally. 

When this happens, you can simply remove the duplicates. But before that, ensure that you categorize and match the transactions in your account. 

Once the bank is connected and you see duplicates, you can simply exclude and delete them in the For Review tab. Here's how:

1. Go to the Banking menu and select Banking. Then, look for the affected bank and select it.
2. In the For Review tab, select the box of duplicate transactions.
3. Next, choose Exclude.
4. Then, to permanently remove them, just go to the Excluded tab.
5. Check the box of the transaction and choose Delete. 

Those excluded transactions won’t be added to QBO or downloaded again.

I've attached the following articles for reference about migrating data from QuickBooks Desktop to QBO:

• What to do after you move from QuickBooks Desktop for Windows or Mac to QuickBooks Online
• Learn how features and data move from QuickBooks Desktop to QuickBooks Online

It's also recommended to perform the reconciliation process regularly to ensure the recorded balance in your QBO account matches your real-life bank statement. For a detailed guide, check out this link: Learn the reconcile workflow in QuickBooks.

If you have any other questions about managing bank transactions in QBO, feel free to leave a comment below. I'm always here ready to lend a hand. Have a good one.