Notifications must be practiced by any means allowing the interested party or its representative, have proof of receipt and the date and content of the document notified.
For example, a notification received by post, without proof of receipt, doesn’t produce effects, while the person concerned makes known they haven’t been notified, either expressly or by bringing forward an action against the notified administrative act.
The most common practice is that the Administration notices via certified mail, with proof of receipt. This system allows, in principle, to state that the taxpayer has become aware of the notified administrative act.
However, on countless occasions, the person who signed the acknowledgment isn’t necessary the person involved, but could be another person who may or may not be related to them (family, porter, employee, friend, etc...). Here two basic interests come into play and somewhat contradictory. On the one hand, the person concerned must be aware of the administrative act, furthermore, the necessary streamlining of administrative procedure. In such cases, the applicable regulations stipulate that in the absence of the person concerned, any person who is at home and establishes its identity may take the notification. But for the notice to be valid, it is necessary that the signer of the proof of delivery belongs to the sphere or circle of interests of the person concerned. In another case, the notification has no effect.
A common practice among taxpayers has been to systematically reject letters with proof of receipt sent by the Treasury. This has prevented that the acts issued by the Administration produce effects. To avoid this occurrence, the Law 30/1992 which has recently entered into force, states that "when the applicant or his representative rejects the notification of an administrative action, it shall be recorded in the file, specifying the circumstances of attempting to notify and the process shall be declared as carried out and as following the procedure" In practice, certifying on the record when the person concerned has rejected the notification is an extremely sensitive issue, so those actions of the administration must be analysed very closely in which there may be a loss of taxpayer guarantees.
Finally, the law establishes that when those interested in a procedure, (1) are unknown, (2) the place of where the notification should be sent is ignored or (3) the attempted notification could not have been performed, it will be through means of announcements in the bulletin board of the Town hall corresponding to the last address and in the Official Gazette or Autonomous Community, depending on the nature and scope of territorial administrative act to be notified. Also in this case, taxpayer guarantees should be tightened to avoid malfunctions and abuse of administrative power.