Old business merging with new business

I found a thread that talks about how to handle the selling of a business.  Maybe there is info in there to help you out? 

https://quickbooks.intuit.com/learn-support/en-us/reports-and-accounting/i-am-selling-my-business-do...

Hello there, Patti.

Thank you for reaching out to Community. I'd be glad to assist you in achieving your goal.

You can add the new owner to your QuickBooks Online (QBO) company and transfer the Primary Admin role to them. After doing that, they can modify the new business and tax information in your company file.

To add a new user, here's how:

1. Navigate to Settings or the Gear icon, then Manage users.
2. Click Add user, then enter the user’s name and email address. Note that special characters aren’t allowed other than a period in the user’s name. For the email field, only a period and the @ character are allowed.
3. Select the Roles dropdown, then choose the role you want to assign to the user.
4. Review the features this role gives access to. You can expand each section. And select the Account management settings you want to manage (if applicable for the chosen role).
5. Once done, Send invitation.

After that, you'll have to transfer the Primary Admin role to the new user so they can modify their business and tax information in your company file.

Feel free to visit this article for further details about adding a new user: Add and manage users.

If you have additional questions about managing QuickBooks, just click the Reply button below.