Tax Number 
See tax number.
Country Version Italy covers multiple tax numbers required in Italy for identifying customers and vendors by the tax authorities. You maintain your customers' and vendors' tax numbers in their master records, on the Control data tab (customers) or on the Control screen (vendors), as follows:
Fiscal code (in Italian, codice fiscale)
You enter the fiscal code in the Tax Number 1 (STCD1) field for:
Natural persons: enter the 16-character alphanumerical fiscal code and select the Natural Person (STKZN) indicator
Freelancers (libero professionista) and individuals doing business activities without a company (ditta individuale): enter the 16-digit fiscal code and select the Natural Person (STKZN) indicator
Legal persons (Italian companies): enter your 11-digit fiscal code (and do not select the Natural Person (STKZN) indicator). For legal persons, the fiscal code is usually identical to the VAT number, but there are exceptions
VAT number (in Italian, partita iva)
You enter the 11-digit VAT number in the Tax Number 2 (STCD2) field for:
Freelancers and individual doing business activities without a company
Legal persons (Italian companies)
Digits 8 through 10 represent the corresponding fiscal code for the province.
For all companies that belong to the European Union, you enter the European VAT number in the VAT Registration No. (STCEG) field. For Italian companies, the European VAT number consists of the prefix IT followed by their VAT number, for example, IT12345678901.
Note that freelancers, individuals doing business activity without a company, and legal persons have both a fiscal code and a VAT number, and you must enter both a fiscal code and a VAT number.
You enter your own fiscal code and European VAT number in Customizing, by choosing . Choose your company code and enter data as follows:
Enter your European VAT number in the VAT Registration No. field
Choose Additional Data and enter your fiscal code in the Tax Number field