What does it certify?
This certificate will be issued if the data in the AEAT confirms your tax residence in Spain. A distinction must be made between countries of residence where there is an Agreement and those where there is not.
In the certificates of tax residence in Spain for countries with an agreement, the Spanish tax authorities certify that you are a resident in the sense of the agreement between Spain and the country of residence.
In the certificates of tax residence in Spain for countries without an agreement, the tax authorities in Spain certify that you are a resident in Spain.
In both cases the certificate will be issued in Spanish and English.