A NIE is a tax ID not an Identity Number… The NIE is a commonly used term for the green card issued to EU passport holders. If you are an EU/EEA citizen and would like to stay longer than 90 days in Spain, then you will have to register with the authorities to get a NIE “residence card”. The correct legal term to call it is “Certificado de Registro EU” -EU residency certificate aka NIE green card. This is a green paper card that cannot be laminated. It contains your name, date of birth and location of birth, address in Spain and date of application. NIE stands for Número de Identificación de Extranjero (identification number for foreigners) and is for everyone who isn’t a Spanish citizen. The NIE is always one letter followed by 7 numbers, and then another letter- e.g. X-7654567-C. It’s a number that identifies you as a foreigner in Spain. This number is required for any legal and financial work in filing taxes, buying property, establishing a business, opening a bank account, and for almost all other forms you fill out. You need a NIE to make any kind of transaction or payment that might involve the Spanish Tax Offic In sum, all foreigners need a NIE number, regardless of their nationality. Then, if you want be a resident, non-EU nationals can get a document called TIE, while EU-nationals should get a “Certificado de Registro de la EU”.