How do I change/add the field description to suit , for mapping. I need a field for apartment number and another for extra street?

I'm here to help you add other fields, mike-bizsupport-.

When you import a customized template into QuickBooks the customer's shipping and billing address is the only option in mapping the fields. We can add a custom field within QuickBooks so it appears when you create, print, and email the invoice. 

Let me show you how:

1. From the Gear icon, click Account and Settings.
2. Click Sales from the left menu.
3. Select the Sales form context section.
4. Under Custom fields, enter a name something like Apartment No. Then, click the Internal and Public box.
5. Click Save and then Done.

Let's create an invoice on how it looks like. For more details when importing and customizing your sales form, refer to these articles:

• Import custom form styles for invoices or estimates
• Add, customise, or remove logos on sales forms

Get back to me if you have other questions. You take care and have a nice day ahead!