Hello Srhode,
Given the details you've provided in your question about the vendor and the specifics needed for POs, I can see how having the option to assign a template to specific entity in QuickBooks Enterprise would be useful. These kinds of automation options can help with saving time as well as ensuring accuracy of information for your forms. I'll go over this with you.
In QuickBooks Desktop, it's possible to create custom form templates for many transaction types, including purchase orders. The customization options available help with formatting your forms to include the information you need for various circumstances. Some of the fields will pull from the customer or vendor profile, and then there are custom fields that you'll be able to fill out manually. This article goes over the customization options: Use and customize form templates
Being able to assign the purchase order template style is a great idea, but it's not something that's currently available in the program. I encourage you to share this idea by leaving feedback using the following steps: select the Help menu in QuickBooks, then choose Send Feedback Online.
In the meantime, manually selecting the specific style you need for that vendor's purchase orders when you enter them is the way to accomplish what you need. It may even help to name the template a specific way so it stands out from other purchase order styles and doesn't get confused. To make sure you have the correct one, you can always click Preview from the down-arrow below the Print button on the transaction window.
Enjoy the rest of your day!
