I need to change my products and services back to using sub-items from categories. It is too difficult to find parts with categories. How can I do this?

You will need to reenter all transactions if you will create a new QuickBooks Online account, mharvey1.

This is because there's no feature to directly transfer or import transactions from one account to another, except or invoices and banking transactions. Also, QucikBooks Online does not have a sub-item option. This feature is only available in QuickBooks Desktop.

If you're using the Desktop version (QuickBooks Premier, Enterprise, or Accountant), you can use the Inventory Assembly feature to use or set up sub-items. You can use this article as a guide: Combine Your Inventory Items To Build Finished Goods.

Please don't hesitate to reach out to us again or add a reply below if you have follow-up questions. 

@mharvey1 

You may open a new QBO account

https:// quickbooks.grsm.io/US
https:// quickbooks.grsm.io/us-promo

then utilize a 3rd party tool to migrate data from your old account

https:// transactionpro.grsm.io/qbo

As an additional option, consider having an inventory management app if you are trading merchandises.