SII
The SII (Suministro Inmediato de Información, Immediate Supply of Information) is the Spanish Tax Agency system through which certain companies send the records of their issued and received invoices electronically within a few days of issuing or recording them, instead of filing VAT books.
Who must use the SII and what does the invoicing program have to do?
Large companies, VAT groups and companies registered in the monthly VAT refund register are obliged to use it, and any other company can opt in. In practice, the invoicing software has to generate and send the records in the structure set by the Tax Agency and handle the responses: accepted, accepted with errors or rejected.
Where it appears in W3ERP
W3ERP sends the SII records to the Spanish Tax Agency from the sales, finance and production module, based on the issued and received invoices already recorded in the system. Alongside the SII are the tax module and the communication with the tax office and with banks.