As for your other question, you can manually upload bank transactions into QBO. If your financial institution offers a WebConnect file, you can sign in to their
website and follow the online process for downloading transactions.
Once you're ready, then let's upload the file to your company. Here's how:
Go to Banking on the left pane.
Choose Banking at the top then click File Upload (see screenshot below). If you’ve never connected an account, select Upload transactions manually at the bottom of the screen.
Click Browse and choose the WebConnect file.
From the QuickBooks account drop-down, select the account you want to upload the bank data and then click Next.
Note: If you don't have accounts set up yet, select Add New then add an account. If you're uploading a CSV file, you're prompted to select columns from the CSV file that match QuickBooks Online banking fields. Then, click Next when you're done.
Select Let's go! or Finish depending on what you see.
In regard to the reconciliation process, you can start with the oldest bank statement that hasn't been reconciled, and keep going until you reach the most recent statement. Since you're reconciling, you might want to check out this helpful article.