a) Documentation that has changed.

See the Versions section, which details the new features for each technical modification.

Technical Import Guide CAU V 3.11
Rules and Conditions for Importing CAU V 4.0
Additional Information Import CAU GENERAL V 3.13
Additional Information Import CAU RR.EE. V 1
Web Service Guide for Submitting Documentation. V 1.7
CAU Import Consultation Technical Guide V 3.3


The programming changes will be uploaded to PROducción on Wednesday, June 18, 2025.
It is now in PRE-production.

It can be seen in:

HEADQUARTERS: Tax Agency: Technical Guides - Submission of the Single Administrative Document ( SAD )

b) Definitive closure of the current PreCau duo.

See news published on June 4, 2024 (H1 publication of technical documentation andcalendar). Here the day 10/14/2025 is detailed as the day of thedefinitive and irreversible closureof the current PreCau duo as regardsupon registration of newfull or simplified declarations.

c)Email for inquiries: H1.info@correo.aeat.es