The concordance certificate or “certificado de concordancia” is the document that verifies, once you have obtained the Spanish nationality and your DNI, that you are exactly the same person who previously had an NIE and residence card as a foreigner.
That is to say, during your entire period of residence in the Spanish territory you have used a TIE and a specific NIE number to identify yourself before different public administrations and private institutions. We are talking about banks, the Social Security or the Immigration Office, for example.
However, when you get the Spanish nationality, your ID documentation changes: instead of having a TIE you will have your Spanish DNI, which contains a DNI number (different from your NIE), in addition to receiving a new passport number.
And there is not only a change in your identification number in the country, but more.
In many occasions with the Spanish nationality you start to legally have a second surname (your mother’s first surname); so your self within the registries is doubly altered.
This will make all these private and public institutions that had you registered with your TIE and NIE have to update their records to verify that you are the same person (although now with a new document and identity number).
The certificado de concordancia is the document that allows this identification and verification.
