SAFTCheck Field Notes
Practical guides on Portuguese SAF-T submission, ATCUD format, encoding pitfalls, and AT deadlines.
2026-05-02 · 4 min read
How to fix the SAF-T UTF-8 encoding error in Portugal
Why AT silently rejects SAF-T XML files declared as UTF-8, and the one-line fix that makes them go through.
2026-04-09 · 3 min read
ATCUD format errors and how to fix them
The 8-character validation code, the dash, the sequence — what AT expects since 2023 and the patterns that fail.
2026-03-12 · 5 min read
SAF-T submission deadlines and AT rejection workflow
Monthly billing SAF-T due day 5, what changed in 2024-2026, when the QES mandate kicks in, and how to recover when AT rejects.