I operate a numbered company with several companies operating under the numbered company can I create more than one estimate/invoice template for each subsidiary company

Hi stonecitypolelines,

Glad to have you as a new member in the Community. I'll be happy to assist so you're on the right track for achieving your goals. 

QuickBooks allows you to add and use custom templates. To do this, click on the Gear icon > Custom Form Styles > from here you can add the templates for each of the companies in question. Once you've added the templates, you can then choose to use any of them when creating an estimate. 

For reference, here's a helpful article that shows you how to: Customize estimates in QuickBooks. 

Let me know if this info helps. I'll be a message away in case you have other questions. Otherwise, I wish you a great rest of the day!