Revision 1.17 of the AES Export Declaration Web Services Guide for the exchange of information between Operators and Customs in the new AES (Automated Export System) is published. This guide contains the messages of the external domain (communication between the Economic Operator and the Tax Agency) of the national component of the Automated Export Declaration System AES, as well as the adaptations that may be necessary to improve the National Export Systems in line with the Union Customs Code (UCC).

This new revision changes the effective date of the definitive period, adjusting said entry to 23:59:59 on 14/12/2025 (UTC time), and announcing a time of unavailability for the filing of declarations from 23:59:59 on 14/12/2025 until 01:00:00 on 15/12/2025 peninsular time (CET), to avoid problems with this time difference between UTC and peninsular time (UTC + 1).
It is recalled the importance of the moment in which the system enters a definitive state, the need to test the validations of the definitive period and that it is important that all operators have their systems correctly configured to validate the rules and conditions based on that date, taking into account that all registrations of declarations admitted on December 15, 2025 must be in the definitive period format.