Law 39/2015:
Article 28. Documents provided by those interested in the administrative procedure.
“3. Administrations should not require interested parties to submit original documents, unless, exceptionally, the applicable regulations provide otherwise.
Likewise, public administrations do not require interested parties to provide data or documents not required by the applicable regulations or which have previously been provided by the interested party to any Administration. To this end, the interested party must indicate at what time and before which administrative body he submitted the aforementioned documents, and public administrations must request them electronically through their corporate networks or by consulting the data intermediation platforms or other electronic systems enabled for this purpose. It is presumed that such consultation is authorized by the interested parties unless the procedure expressly states their 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 may ask the interested party to provide them again. ”
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:
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d) Failure to submit 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 prepared by them. [...] ”