credo che corrisponda a questo

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Note added at 20 min (2012-07-06 20:11:31 GMT)
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o
codice identificativo fiscale/codice fiscale della società

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Note added at 21 min (2012-07-06 20:12:02 GMT)
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www.google.com/adsense/taxinfo?hl=itAziende non U.S.A. (nessuna attività basata negli Stati Uniti): le attività del ... È richiesto un codice identificativo fiscale valido negli Stati Uniti, quale il TIN ...

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Note added at 21 min (2012-07-06 20:12:18 GMT)
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avvocatiamericani.it/Visto L-1 o L-2 : per trasferimento di Personale da un azienda all'altra .... essere svolta da un legale U.S.A., bisogna ottenere il TIN (codice fiscale della societa').

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Note added at 36 min (2012-07-06 20:27:12 GMT)
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Incorporation Numbers
An incorporation number, more often called a Federal Tax Identification Number (TIN) or an Employer Identification Number (EIN), is the federal number assigned to a business by the Internal Revenue Service. The Internal Revenue Service requires every corporation or partnership to have one. The number is used by the federal government to identify the business for tax reporting purposes. Most businesses, depending on legal structure, will also need the number for such things as opening a business checking account, obtaining business credit or hiring employees. Like a Social Security number for individuals, each incorporation number assigned is unique and is issued exclusively to that particular business.
http://smallbusiness.chron.com/incorporation-number-34550.ht...