Uploaded expenses manually already (contractor ACH payments) and paid invoices (ACH credits). If I connect the bank account now, will these transactions show up twice?

Thanks for sharing the details with me, @ohiogastransport.

And yes, the transactions will show twice if you connect your bank account to your QuickBooks Online (QBO) account. However, you can undo the transactions from the For Review tab to avoid duplicate entries in your banking feeds. Let me guide you how.

To connect your bank account to your QBO account:

1. Go to the Banking or Transactions menu.
2. Select Connect Account or Add account/Link account if you've already created an account.
3. Search for your bank.
4. Click Continue.
5. Follow the onscreen instructions and select Connect.

You can also check this article for more details: Connect bank and credit card accounts to QuickBooks Online.

Once your bank is connected, QBO will automatically download the last 90 days of transactions. To view this, you’ll want to go to the For Review tab. From there, delete the entry you’ve already uploaded to avoid duplication.

Here’s how:

1. Go to the Banking or Transactions menu.
2. Select the blue tile for the account you want to review.
3. Click the For Review tab.
4. Locate and select the transaction you’ve already uploaded and select Excluded. 

For more details about this, check the Exclude personal or duplicate transactions section in this article: Categorize and match online bank transactions in QuickBooks Online.

You might also want to check this link that you can use for reference when you’re ready to reconcile your accounts in QBO.

You can always get back to me whenever you need help with your banking feeds or with your QBO account. I’m just a post away from you. Keep safe.