Is there a way for QB to search for possible duplicate transactions? I may have imported and accepted numerous duplicates.

I appreciate you reaching out to the Community, @elizabeth_hollin.
 

Here's how to find your duplicate expenses in QuickBooks Online:

1. Go to Expenses. 
2. Select the NO. column to sort your transactions.
3. Check for duplicates.

Once done, you can run a vendor report to see a list of your bills, checks, and other transactions listed in numerical order. You can check this article for more detailed steps: Find duplicate transaction numbers in QuickBooks Online.

I've also added this article that you might find useful in making sure that your accounts are matched and accurate in QuickBooks Online: Categorize and match online bank transactions in QuickBooks Online.

Keep me posted if you have further questions with your transactions. We're available 24/7. Have a great day!