How to change transaction dates in QBO? 10% of uploaded bank statement lines w wrong date 12/31/1969. i excluded, edited, accepted, but still wrong in reconciliation

I'll share some details about modifying the date of the downloaded bank transaction, Terri.

Once a transaction uploads, changing its date isn't possible. Instead, we can undo the transactions in the register, exclude those in the Review tab, and re-upload the file.

Before uploading, please check the date format in the CSV file to ensure it's correct. Make sure dates have the same recommended dd/mm/yyyy format. I'll outline the steps below to re-upload the file.

1. Go to Transactions in the left panel, then select Bank Transactions.
2. Select the Link account dropdown, then Upload from the file.
3. Click Drag and drop or select files and select the file you downloaded from your bank. Then, select Continue.
4. In the QuickBooks account dropdown, choose the account you want to upload the transactions into. Then, click Continue.
5. Follow the onscreen steps to match the columns on the file with the correct fields in QuickBooks. Then tap Continue.
6. Choose the transactions to import. Then select Continue.
7. Click Yes and Done.

Check out this article for more details in reviewing the format and file: Manually upload transactions into QuickBooks Online.

When you're ready to reconcile your bank, you may check this article for the workflow: Reconcile an account in QuickBooks Online.

Let us know if you have other questions about transactions. We're always here to help you out.