Do you know why it would happen when creating an invoice, that some of my accounts listed within my Chart of Accounts are not populating in the Product/Service dropdown?

Hi, @nat 

Chart of Accounts do not populate to an Invoice, your Services and Products do.  Can you give us a little more info on what you're trying to do and someone here should have an answer for you. 

If you're now to QBs, here's a quick over view of invoicing.

First you want to create your Services and/or Products that you'll be charging your Customers for.  (Sales > Product & Services > New...   follow the prompts.)  This is where your Chart of Accounts can be accesses to correctly categorize your items.

Once you have the list of what you're selling.  (Dashboard > Invoices > Select/Create Customer... )  From here you'll add in your Product or Services and modify anything else that is appropriate for this Customer. 

I know that both the above creating Services/Products and the invoice is really brief, but it's not going into detail if you already know how and it's not really your question.  But if it is what you're looking for, hopefully it will get you started.  If not, searching on either of the above will get you a lot more details.