I migrated my data from desktop to online. When I added my bank account data later, I now have to two bank accounts. How can I fix this

Thanks for joining the Community space, dontheo. I'd be glad to provide you with the steps to disconnect your bank in QuickBooks Online.

Here's how:

1. Go to Bookkeeping, select Transactions, then Bank Transactions.
2. Choose the tile for the bank account.
3. Select the pencil icon, then select Edit account info.
4. Tap the Disconnect this account on the save checkbox. 
5. Select Save and Close.

You can find complete instructions on disconnecting or deactivating a bank account in QBO by visiting this article: Disconnect accounts connected to online banking in QuickBooks Online.

Once done, you might want to consider reconciling your bank account to ensure your account is balanced and accurate: Reconcile an account in QuickBooks Online.

Please let me know if you have additional questions or concerns about your bank accounts in QBO. You can reach out to the Community at any time. Have a good one!