N.I.F número de identificación fiscal
This is the tax identification number, required for anyone who makes cash transactions in Spain, that could have fiscal consequences , even theoretically. For example, this number is usually required to open a bank account. This number is provided by the Spanish police and thereafter registered automatically with the Spanish tax office (= hacienda). For Spaniards this number (número de identificación fiscal) is called N.I.F. and for foreigners N.I.E.(número de identificación extranjero).