I appreciate the update that you gave, @Imagine That1.

I'd like to make sure that you'll be able to process a Purchase Order with no issues in QuickBooks Online.

Assigning the billable account to a single account should do the trick and fix this matter. I'd recommend performing the other solutions presented by my peers above, especially the steps shared by MirriamM.

If the same thing happens after following the steps, I'd suggest reaching out to our Customer Care Team. They have the tools that can help isolate the reason behind this matter.

To do that:

1. Click on Help at the top menu bar.
2. Select on the Contact Us button.
3. Enter a brief description of the issue in the What can we help you with? box.
4. Press on Let's talk.
5. Select on Get a callback.
6. Key in your contact details, then tap on Confirm my call.

For your reference, I'm also adding here some resources about managing purchase orders in QuickBooks Online:

• Learn how to create purchase orders and send them to suppliers
• Learn how to add an accepted purchase order to a transaction for your supplier

I'd be pleased to assist you should you need anything else with PO. Just leave a reply below and I'll take care of you.