How do I reconcile an account missing transactions because 8 old statements are unavailable electronically only pdf? Current balance is correct but historic data missing.

I can provide you with a solution for the bank transaction you're having trouble with.

Alternatively,  you can visit our Apps store and look for a third-party app that integrates well with QBO and lets you convert your pdf to CSV file. 

You can check the customers’ reviews to get a better comparison of each app. Then choose the one that best suits your need the most.

I also invite you to visit the QuickBooks Blog to keep you in the loop on the latest news about the product. From there, you'll see the features added to QBO and resources to help your business thrive.

After that, you can categorize them in order to allocate them to the appropriate account. As a starting point, consider the following article: Categorize and match online bank transactions in QuickBooks Online.
 

I'm also adding these articles for reference:

• Fix issues at the end of a reconciliation in QuickBooks Online. Go to the Step 5 section.
• What to do if you can’t find downloaded transactions in QuickBooks Online. Follow Step 2 if you still can’t find the transaction.

Once you have all the transactions, try to reconcile the account again. You can watch a video tutorial in this link: Reconcile an account in QuickBooks Online.