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SII AEAT for Spanish firms: scope and deadlines
SII AEAT for Spanish firms: scope and deadlines By Ivor Padilla, co-founder of Gradion · Published on 11 April 2026 · Last updated: 11 April 2026 · 10 min read When someone inside a Spanish accountancy or tax firm searches for SII AEAT, they are usually not looking for a textbook definition of