Law 39/2015:
Article 28. Documents provided by those interested in the administrative procedure.
"3. The administrations must not require the interested parties to present original documents, unless, exceptionally, the applicable regulations establish otherwise.
Also, the public administrations do not require data or documents from the interested parties that are not required by the applicable regulations or that have been provided previously by the interested party to any Administration. For these purposes, the interested party must indicate at what time and to which administrative body he presented the aforementioned documents, and the public administrations must request them electronically through their corporate networks or by consulting the data brokerage platforms or other electronic systems enabled for the purpose. It is presumed that this consultation is authorized by the interested parties unless the procedure states their express opposition or that the applicable special law requires express consent; in both cases, they must be informed in advance of their rights regarding the protection of personal data. Exceptionally, if the public administrations cannot obtain the aforementioned documents, they can ask the interested party again to provide them."
Article 53. Rights of those interested in the administrative procedure
"1. In addition to the other rights provided for in this Law, those interested in an administrative procedure have the following rights:
[...]
d) Not to present data and documents not required by the rules applicable to the procedure in question, which are already in the possession of the public administrations or which have been drawn up by them. [...]"