What is VAT Identification number?

Only subscribers in countries of the European Union (EU) except Germany, need to disclose their VAT number. This is for proper handling of the VAT

EU-State	Name of VAT-Nr in contry's language	Abbr.	syntax of VAT-ID-Nr
			country code	# of further digits
Belgium	Numéro T.V.A / BTW-Nummer	N° TVA / BTW-nr	BE	9
Denmark	Varemodtagers moms-nr	SE-nr	DK	8
Germany	Umsatzsteuer- Identifikationsnummer	USt-IdNr.	DE	9
Finland	Arvonlisäveronumero	ALV-nro	FI	8
France	Numéro d'identification TVA	ID. TVA	FR	11
Greece	A.ø.M. (Tax Registration N°)	A.ø.M.	EL	8
Ireland	VAT Registration Number	VAT REG NO	IE	8
Italy	Codice IVA (Numero Di Partita IVA)	P.IVA	IT	11
Luxemburg	Numéro d'identification TVA	ID. TVA	LU	8
The Netherlands	Omzetbelastingnummer	OB nummer	NL	12
Portugal	Numero de identificacao fiscal	NIPC	PT	9
Austria	Umsatzsteuer- Identifikationsnummer	UID	ATU	8
Sweden	Moms Registrerings Nommer	Moms Reg. No.	SE	12
Spain	Numero De Identificacion Fiscal	N.I.F.	ES	9
UK	VAT Registration Number	VAT REG NO	GB	9 to 12

Source/Quelle: IHK Rostock