NIE, Certificado UE, TIE? What are the differences between them?

Certificado UE, the “green card”

Citizens of a Member State of the European Union or another State that is part of the Agreement on the European Economic Area and Switzerland have the right to reside in Spain for a period exceeding three months if they meet a series of requirements. For this they will get a green card that is called Certificado de ciudádano de la Unión Europea, which can be temporary or permanent. Similarly, this right of residence is also applicable to family members, whatever their nationality is, if they accompany or are going to reunite with a citizen of a Member State of the European Union or of another State that signs a party to the Agreement on the European or Swiss Economic Area that meets the conditions.

Residence card, Tarjeta de residencia or TIE

It is an identity card for foreigners (made of plastic), which contains your photo, type of residence, etc.
Unlike the EU certificate, the residence card is admitted for people who are not citizens of a State of the European Union, the European Economic Area or Switzerland, or relatives of citizens of these countries to which the regime applies of Union citizen. It is normally acquired, for example, when a visa or authorization to stay in Spain for more than six months has been issued. Unlike the EU certificate, which is a (paper) card for people from an EU member state, which is processed without the need for a visa and for the mere fact of residing in Spain for more than three months.

NIE

The NIE is the Foreigner Identification Number, it is an administrative document issued by the Police that administratively identifies us with the organs of the Spanish state. A foreigner can have a NIE, although he would not have legal residence in Spain. It is not the same as an authorization to reside in Spain, as it is only an identification number for a foreigner before the administrations and before other institutions, such as banks and it is obtained before a residence authorization. With the NIE, there is the possibility of opening a bank account, registering a company and hiring a mobile connection in Spain, before obtaining legal resident status.