From MCHM Abogados, we strongly recommend extreme caution. While you have the right to submit any administrative application on your own, regularization under Additional Provision 21 requires a high level of technical expertise. Submitting only a passport and a padrón is usually insufficient. The Immigration Office requires structured evidence, properly apostilled certificates, and legal argumentation proving you strictly meet the criteria of RD 1155/2024. A denial now can close doors for you in the future. We advise you to consult with us to evaluate the viability of your case before taking any missteps.