Greetings, @123146175636639.

It's nice to have you here in the Community. I can share some information about customizing form styles in QuickBooks Online (QBO).

Currently, customizing Purchase Order comes directly from the Master Form Type template, regardless of which template you have set as default.

Here's how:

1. Click the Gear icon at the top, then pick Custom Form Styles under Your Company.
2. Choose Edit on the right side of Master form type (or Standard form name) under Action.
3. Make the necessary changes.
4. Select Done.

While QBO doesn't have the option to add a new style for Purchase Orders, I encourage you to submit feedback. These requests and suggestions are forwarded to the Product Development Team for consideration in future updates. This can be done directly through your account by clicking the Gear icon in the top right corner, then select Feedback or by going to the following link: QuickBooks Online Feature Requests. I'm going to submit feedback from my side as well.

That's it! Thanks for being a part of our QuickBooks family. I'd be glad to answer should you have any follow-up questions. I'm always here to help. Enjoy the rest of the week.