You can apply for the Argentine nationality at a Consulate or while in Argentina.
To apply while in Argentina, your need to complete THREE STEPS with the Civil Registry in Ciudad de Buenos Aires (CABA) and with RENAPER.
STEP 1) CIVIL REGISTRY IN CABA
*It must be the Civil Registry in CABA and not any other as this one registers the births occured abroad.
You can do this in person or online. For further information, visit https://www.buenosaires.gob.ar/tramites/inscripcion-de-partidas-de-extra...
a) In person: you should attend Mesa de Entradas of the Civil Registry in Ciudad de Buenos Aires (Uruguay 753, piso 1°, CABA) with the required documents to register your birth and a "nota de referencia" about the Argentine nationality obtained.
b) Online: you should visit https://www.buenosaires.gob.ar/tramites/inscripcion-de-partidas-de-extra... and enter the platform of online procedures (plataforma de trámites a distancia -TAD-) of CABA, using a "Clave Ciudad" (you need an Argentine tax payer number for this), and start the procedure named "Inscripción de Nacimientos y Defunciones en Extraña Jurisdicción". To obtain a "Clave Ciudad" you only need an active Argentine tax payer number.
STEP 2) RENAPER
For further information, visit https://www.argentina.gob.ar/servicio/optar-por-nacionalidad-argentina-p...
At the appointment with RENAPER you will apply for the Argentine nationality and a DNI, and will be given a certificate to proof you have obtained the nationality.
STEP 3) CIVIL REGISTRY IN CABA
Just like for step 1, you can complete this step in person or online. This time, you should request a "nota de referencia" stating that the holder of the birth certificate has been granted the Argentine nationality.
ATTENTION: If you do not complete the THREE STEPS, you may not be able to carry out other procedures in the future (DNI renewal, passport application, etc.).
Both for procedures before RENAPER and the Civil Registry, you should submit:
- DNI of both parents (in case of minor applicants. Should one parent be a foreigner, they should submit their passport) / DNI of the parent transferring the nationality (in case of adult applicants);
- birth certificate of the parent transferring the nationality;
- British birth certificate with an Apostille;
- certified translation of the apostilled British birth certificate, done by a certified translator in Argentina with the relevant legalisation by a Translators Association (Colegio de Traductores Públicos);
- birth certificate issued by the Civil Registry in CABA (for steps 2 and 3);
- document issued by RENAPER on completion of the appointment with said entity (for step 3);
- any other document requested by RENAPER or the Civil Registry.