Can I delete a bank account I linked twice?

Yes, you can delete the bank account you linked twice in QuickBooks, @darlingsoaps2021. It's my pleasure to present the detailed steps.

I'll make sure you can remove the duplicate checking account in your account. This way, your balance will be accurate in no time in QuickBooks Online.

Before we proceed, make sure to categorize or exclude all the appropriate transactions on the Banking page. Please note that disconnecting the automatic online banking updates will delete any transactions in the For Review tab.

Once done, follow the steps below to disconnect the account:

1. Go to Banking on the left pane. 
2. Choose the duplicate checking account and click Edit (pencil icon).
3. Select Edit account info.
4. Check the box next to Disconnect this account on save.
5. Hit Save and Close.

For more details, see this article: Disconnect or delete an account from the Downloaded Transactions page.

Further, don't forget to reconcile your bank account to make sure they match your bank and credit card statements. 

Moreover, check out these articles below on how to fix reconciliation and bank issues in QuickBooks: 

• Fix issues the first time you reconcile an account in QuickBooks Online
• What to do if you get a bank error or can't download transactions in QuickBooks

Don't hesitate to tag my name in the comment section below if you have other concerns or questions about your bank accounts. I'm always ready to help. Enjoy using QuickBooks, darlingsoaps2021.