The new version of the Merchandise Registration Notification (NIM) guide is published in the declarant's records. Testing can be done in the PREproduction environment from 01/15/2024. In PROduction it will be on 01/07/2024.

See in Headquarters of the AEAT the document " Technical Guide for Notification of Registration of Goods V 0.4 " Tax Agency: Technical guides - Notification System for Registration of goods by holders of registration ...  

Due to this, and due to its relationship with the import declaration adapted to the Union Customs Code, this has been modified to allow the declaration of Merchandise Registration Notification (NIM). To do this, it is recommended to see the AEAT Headquarters in the document: " Complementary information Importation CAU V3.4" section "Separata 1. Precedent Document. Box 1201." which explains the special case of the declaration of the NIM document ( Merchandise Registration Notification)

Tax Agency: Technical guides - DUA Presentation (Single Administrative Document)

Note; The calendar has no variation. It can be consulted in the news published on 06/21/2023: https://sede.agenciatributaria.gob.es/Sede/en_gb/aduanas/novedades/2023/ CAU_import_declarations_and_prior_despacho_notification.html