Easiest way to separate multiple companies that someone has comingled together in Quickbooks?

Unfortunately there is no an easy way. You can use a 3rd party migration tool to speed up the process. It;s a one time license.

https://get.transactionpro.com/qbd

Asking on here was my last hope to see if someone else knew a trick to help - Thank you!

Hi there, @Cobbs. 

I want to ensure you can split those multiple companies on your QuickBooks Desktop.

I'd also agree with what 4Gal has recommended above. You'll want to consider using a third-party app to separate those companies. Check the Apps Center and pick one that matches your needs.

Here's how:

1. From your browser, enter this link: Apps for QuickBooks Desktop.
2. Then, enter a keyword in the Search field or use the Filters section to narrow down the process.
3. This action will display a list of apps.
4. Click on the View Profile button to see more details about the software.

As for which app you can use, although we're unable to recommend which ones to use, you can view an app's rating (stars at the bottom of the app's name). You can also open the app's page and read the user's comments on the app in question. This should give you a general idea of whether an app meets your company's standards.

Moreover, you can visit this article to learn how to manage your data with QBDT: Import and export data in QuickBooks Desktop.

Let me know how else I can help you organize your company by commenting below. I'll always be ready to assist you. Stay healthy and hydrated.

@Cobbs 

Are the businesses sole proprietorships or ???  Do the businesses have separate bank accounts at least?  Did the previous bookkeeper use classes or anything to differentiate the transactions between Co. A, B, C, and D?  Using a 3rd party importer will help but it won't do you any good if you can't determine which transactions go with which company.