I'm here to share some information about handling purchase orders, creating a bill and adding it to invoices, @RASCLC. 

Yes, you can run the reports mentioned by MaryAnn_E above to check any open purchase orders that you have per vendor. From there, you can create a billable expense. Then, add it to an invoice to ask for reimbursement from your customers. 

For more information about billable expenses, check out this article: Enter billable expenses. That will show you how to turn on billable expense tracking, create a billable expense out of the purchase order, and then add it to your invoices. 

Once you've received their payment, here's how to record invoice payments in QuickBooks Online. 

Let me know if you need further help with your purchase orders, bills, and invoices. I'm always here to help. Have a wonderful