Ok I'm afraid I'm going to add two additional requirements, based on my experience in IRELAND.

There is VAT added on the cost of SHIPPING. Here's an example (using Irish VAT rates).

Widget      80.00 
Book        15.00 

Shipping     5.00 
------
Net Total: 100.00
VAT:        19.88 
TOTAL DUE: 119.88

Note: The line item prices are all EXCLUDING VAT (the term is "ex VAT" or "Net" in Irleland).
In this example, Widgets and shipping are in the 21% rate and Books are 13.5%.

As mentioned in previous posts to this thread, the VAT Breakdown must appear on the invoice. This shows what was charged at each rate. In Ireland, it normally appears in a box on the invoice, separately from the total figures above, but that isn't necessary, as long as it appears in some form:

Net at 21% :   85.00 
VAT at 21% :   17.85 

Net at 13.5% : 15.00 
VAT at 13.5% :  2.03

Finally, a second requirement, which I think is a "nice to have" and not related to EU regulations, is that some of the invoices I get from Irish suppliers show a VAT code on each line item. So in the example above, the invoice would look like this:

Widget   [1]  80.00 
Book     [2]  15.00 

Shipping       5.00 
------
Net Total:   100.00
VAT:          19.88 
TOTAL DUE:   119.88

VAT Breakdown:
Code Rate    Net     VAT
0     0%      0.00   0.00
1    21%     85.00  17.85
2    13.5%   15.00   2.03

Shipping doesn't display its VAT code "[1]" while the line items do. This is based on the invoices I have received, but I think it would be better if Shipping did display like this:

Shipping [1]    5.00