Under Settings - Finances - Invoices - Options you can specify multiple sales taxes.
Under "Standard accounting area" you can set an existing accounting area as the default, which is always displayed to you. Simply select the desired accounting area and then click on the button "Update standard accounting area".
Under "Display settings' you can define further options for your invoices by activating the respective checkbox. However, the settings only apply to your user. The first option "Show model/item number in position" means that in the fourth step of the invoice creation (read more here) the item number is displayed next to your product. If you activate the setting "Insert last item at the top", the last product added is always listed at the top when there are several products (items) in your invoice.
