Before starting, I'd like to say that I am Italian and I live in Italy.
The Italian customs work exactly like the rest of Italy: the bureaucracy is extremely daunting and overly complex; even the simplest operations require signed forms, written statements, and validation from one or more national security agency ("Guardia di Finanza, divisione importazioni e dogane", "Guardia di Finanza, divisione commercio e artigianato", "Polizia Doganale", "Polizia Postale") whose jobs largely overlap, usually in the most troublesome way. Moreover, depending on the shipment method, you end in different customs offices and the custom procedures, even if documented by the same law, are handled differently - due to the interaction between the various security agency. In any case, as it is common here since the 1946, the actual laws involved in the proceedings are of little or no concern.
How things actually work
SHIPPING BY SEA
Almost anything shipped by sea is going to pass the customs at Genova port (even if the package is going to go to Napoli), where the items are piled in large warehouses and kept there until the customs proceeding can take place. At least 10% of the item stored here are actually lost, damaged beyond recovery or even stolen. The Genova customs also has a tendency to insist on the fact that the declared price for the item is not "right" and that you must provide a proof of purchase in the form of a "Fattura" or a "Ricevuta Fiscale" - thing that may impossible if the item was obtained from an online auction. A credit card statement rarely counts as a proof of purchase. Sometimes (beyond any reasonable logic) a simple printout of an e-mail, sent by fax or by "Lettera Raccomandata" is considered a valid proof of purchase. in other unlucky cases, nothing will do for the customs agent and you end up in HAVING to abandon the item, because nothing you can provide is considered a valid proof of purchase to calculate the fees - note that, completely absurdly, what is good or not is TOTALLY IN THE HANDS OF THE CUSTOMS AGENT.
At one time I had to abandon a complete Apple/// (including monitor), obtained from eBay for around $50, because the customs agent didn't believe a 30kg item shipped from USA could be worth only ~€50 and no document I could provide convinced him; I even risked a fine by saying "Should I fake a document stating I paid €500 for it?".
SHIPPING BY GROUND
Anything shipped by ground is quite likely to come from the EU, so there shouldn't be customs involved, but that's not the case. Ground-shipped items end up in Cuneo customs or Trieste customs no matter what; there, any package with a valid declared value and content is going to pass thru without difficulties -- although sometimes the customs (especially Cuneo) will take the trouble to send you a letter by ordinary mail asking you if you're willing to pay the fees (in this case you MUST FAX or send a "Lettera Raccomandata" with your signature. Even if they provide a phone number, a phone call will not be accepted. If the reply is not quick enough, the package is automatically abandoned - this may well happen because the letter they sent you took one month to arrive and when you get the chance to reply is too late already). For any package whose fee less than €8, you're quite likely to have a surcharge labeled "Costi di Gestione postale" which will raise the total fee around that amount. If the package is not "adequately" labeled, you will receive the usual letter, with a form that asks you to provide (as usual via FAX or "Lettera Raccomandata") a "Classe Merceologica", a price and sometimes a proof of purchase. They're generally far more flexible than the Genova customs, but you can still have some troubles (if something you provide is not compliant, they will often reply via ordinary mail -- and you still face the problem of receiving the letter too late). I actually lost an Apple Lisa serial card in this way: the letter asking for class and price arrived two weeks after the deadline for the reply.
SHIPPING BY AIR
Air mail for the northern Italy arrives at the Bergamo customs. Any package with a reasonable price and description is going to pass thru without difficulties. Items with customs fees up to €30 are shipped right away, more than that and you have to confirm with the usual FAX or "Lettera Raccomandata". The problem with the confirmation letter, obviously still holds...
It is worth to note that items shipped with express couriers are often exempt from these troubles, or at least from the most excruciating details of the rituals, as the couriers' agents are going to provide enough details by themselves of simply ask the recipient via a phone call. Large couriers also have "their" customs agents right inside the ports and airports, providing for an "expressway" thru the procedures.
Weird still gets weirder...
- The declared value of a package is often deemed to be "inadequate" only by the size or weight of the package.
- It is illegal to open for inspection a package addressed to an individual, whereas it is perfectly legal to do the same to a package addressed to a company.
- Even if it is illegal, it was quite common for unusual (in size, shape or even PRICE) packages addressed to individuals to be opened and inspected, and you were not going to receive a "Rapporto di Ispezione" NOR a "Mandato di Perquisizione"/"Ingiunzione di Ispezione", even if you should receive BOTH in case of inspection of your package. This practice is decreasing in entity in the last years, but five-eight years ago (well before the terrorism scare), almost every packages I received was opened and inspected -- more often than not, something was damaged or marred during inspection and no report was ever filled.
- The Italian laws actually allow transactions between individuals involving used/recycled items to be exempted from custom fees.
- The customs seem to spend a so insane amount of resources in tracking and checking small packages, that they've no resources left for the large freights: you can (in fact, you really MUST) enter the cargo side of the Caselle airport with your truck to pick up your 300kg freight and all you need is to sign a piece of paper. If you have all your informations and timings right you can have the freight unloaded from the plane straight to your truck.
So...
You should remember these facts when an Italian buyer needs more time to provide a feedback or just to say "Thank you, the package arrived today".
Most of the time, the customer asking the seller to provide false informations (lower prices, etc), or to use the least expensive shipping method is just an inexperienced buyer that realized (after the deal) that the bargain he obtained, after handling/shipping/customs extras is not going to be so much a bargain after all.
Do Italians believe to know better?
There is indeed a certain minority of people in Italy that seems believe to be above the law:
People who still sell items on eBay asking payment via a "Ricarica PostePay" (even if this payment method has been declared illegal by eBay more than a year ago).
People who still believe it is their right to download anything they want with eDonkey.
People who still believe they can tell you how much you should charge them for shipping/packaging/handling or even the item itself.
People who offer you a lower price on an item or service in exchange of not providing you a legal "Fattura" or "Ricevuta Fiscale".
People who ask you to sell them items without a legal "Fattura" or "Ricevuta Fiscale" and with a lower price, with the rationale that you're not going to pay taxes in that way.
But, believe me. Not all the Italians are like that. Most of them are not, no matter how much movies on the Italian Mafia or N'drangheta Hollywood is going to crank out.
So, please, now that you know "how it works" don't stop shipping to Italy on the basis of a bad experience.