Yes, you can bulk reclassify transactions by a single Project, including those from prior closed years, @OM3349. Let me clarify how this works.

In QuickBooks Online (QBO) Accountant and Advanced, you can use the reclassify tool to batch-edit transactions. This tool typically applies to current and open years, but you can adjust the date range to access transactions from prior closed years.

When reclassifying, please note that you can only reclassify transactions assigned to one project at a time. This means you will select transactions under a specific project and then reclassify transactions under another project separately. In QBO Advanced, here's how:

1. Navigate to the Gear icon, then Reclassify transactions.
2. Choose an Account type and the Accounting Basis.
3. Modify the date range in the From: and To: fields.
4. Leave the Type and Modify dropdowns set to All.
5. In the Customer/Vendor dropdown, select the Project name.
6. Click the Find transactions button.
7. Tick the boxes for the transactions you want to reclassify.
8. Click the Reclassify button.
   
    
   

In QuickBooks Desktop, the term Job is used in place of Project. You can also reclassify transactions even if your books have already been closed. You can modify the date range to find and adjust the necessary transactions. In QuickBooks Enterprise Accountant, here's how:

1. Go to the Accountant menu and Client Data Review, then Reclassify Transactions. 
   
2. Set the date range and choose an Accounting Basis.
3. Choose the account you want to View.
4. In the Name dropdown, select the Job name.
5. Tick the box for each transaction you’d like to reclassify.
6. Check the box for either the Account to or the Class to field.
7. Click the Reclassify button.

Both QuickBooks Online and QuickBooks Desktop allow you to create rules to automatically categorize downloaded bank transactions to help speed up your review process. If you wish to know more about this process, check out this article: 

• Set up bank rules to categorize online banking transactions in QuickBooks Online.
• Create rules to categorize transactions in QuickBooks Desktop.

Moreover, to enhance your QuickBooks experience, consider collaborating with our QuickBooks Live Expert Assisted team. These financial professionals specialize in streamlining the reclassification process and providing guidance to keep your books accurate.

Don't hesitate to drop a comment below if you have further questions about reclassifying transactions in QBO. Know that I'm always ready to assist you.