SII (Immediate Supply of Information, near real-time VAT reporting)
The SII is the AEAT system through which certain taxpayers keep their VAT record books directly on the tax agency's electronic portal, submitting the details of each invoice within a few days. It is typical of large companies, VAT groups and businesses in the monthly refund register (REDEME), and being in the SII changes your other obligations: you are excluded from Verifactu and exempt from filing forms 347 and 390.
The logic is that the tax agency already receives your invoicing almost in real time, so both the informative summaries and the Verifactu controls become redundant. For a freelancer or a small SL the normal situation is not being in the SII and following the standard circuit of quarterly returns and annual summaries such as form 347.
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