According to Law 39/2015, of October 1, on common administrative procedure of Public Administrations, when the Administration responsible for a specific procedure has expressly established specific forms to submit requests or procedures, the interested parties they are obliged to use them (article 66.6).
So much so that " documents and information whose special regime establishes another form of presentation are not considered to have been submitted to the register " (article 16.8).
It must be taken into account that the entities that process through EACAT may be considered interested parties in the administrative procedure and, therefore, the previous provisions may also apply to them (depends on the criteria of the responsible Administration of the service).
In this regard, EACAT user bodies can define specific services to facilitate electronic inter-administrative processing that include the forms for the different procedures that make up the service, which are included in the EACAT Procedures Catalogue. On the other hand, when there is no specific procedure in the Catalogue, the EACAT user entities have at their disposal the generic transmission, to transmit the documentation/information that they want to send to the destination entity.
For this reason, it is recommended that before sending the generic submission, you ensure that no specific procedure or specific form of mandatory use has been enabled.
For more information see the following EACAT Support Portal entries: