According to the regulations, when the Public Administration (PA) responsible for a specific procedure has expressly established specific forms to submit requests or procedures, those interested are obliged to use them.
Well, the entities that process through EACAT can be considered interested parties in the administrative procedure and, therefore, the previous forecasts can also apply to them (it depends on the criteria of the AP responsible for the service).
In this sense, 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 entries on the EACAT Support Portal:
Law 39/2015: art. 16 and 66