CF option on small Italian Order

I'd probably just put 'not applicable' and hope for the best if it lets you

You need to ask for it from the shipper,without this customs will either contact the shipper themselves this wasting time it could even just return the shipment.

Thanks for the replies. Have tried entering a few things but no luck. Have asked the shipper about this but I didn't understand the reply:
if you are connected immediately during registration, the state (United Kingdom) will not automatically display the tax code (identification code valid in Italy)

The uk now requires any overseas vendor selling goods to uk consumers for under £130 to collect the vat and pay it to the uk tax office.
Astoundingly, many companies dont want to have the hassle or to pay the fees to register for this 'service' and so only sell to vat registered businesses in the UK.

I have bought from Italy by looking up a random uk company vat number and providing the uk company name and vat number but my address. Probably illegal in both countries, but t least I got the goods.