SII (AEAT)
Immediate Supply of Information on VAT: the record books of issued and received invoices are reported to the Spanish tax authority within the legal deadline, with no manual work.
SII requires the companies it applies to (large companies, VAT groups, REDEME registrants and anyone opting in voluntarily) to report their invoice detail within a few working days of issue or accounting entry. Doing that by hand becomes impossible as soon as there is volume.
Here submissions come from the invoices already in the system, and what really saves trouble is what happens next: the system tracks every submission, validates the tax authority's response and flags records rejected or accepted with errors, along with the description, so they can be corrected within the deadline instead of surfacing in a formal request.
Who it applies to
Who has to apply SII, and within what deadline
The Immediate Supply of Information requires the detail of VAT record books to be reported to the Spanish tax authority within a few working days of the invoice being issued or entered into the accounts, depending on the book.
It applies compulsorily to:
- Large companies, by turnover.
- VAT groups.
- REDEME registrants, the monthly refund register.
Any other company can opt in voluntarily, and in exchange stops filing some informative returns. Anyone applying SII does not additionally have to apply Verifactu, because it serves the same reporting purpose.
What gets reported
The books come from the invoices, not a separate file
Submissions are built from the invoices already in the system: issued, received, intra-EU transactions and capital goods. There is no file to prepare, no exporting between programs and no reconciling the same amounts twice.
That matters because SII is not a summary but a detail: data is reported invoice by invoice, with its tax ID, net amount, rate, tax due and transaction key. Any discrepancy between what you report and what your supplier reports shows up in the cross-check the tax authority itself performs.
Since purchase invoices can come in read by the OCR module and sales invoices are issued by the ERP, the whole chain (document to book, book to tax authority) happens without manual transcription.
Errors and responses
What really saves trouble is what happens after sending
Sending is the easy part. The problem starts when the tax authority replies and nobody reads the reply: a rejected record is still undeclared, and one accepted with errors is wrongly declared, in both cases until a formal request arrives.
The system tracks every submission and stores its outcome with the error description, where there was one. Records needing correction appear in a list, are fixed and resubmitted within the deadline, which is while it still costs nothing.
That tracking is also what lets you answer with facts if you ever have to justify what was sent and when: each record keeps its date, its status and the response received.
Clearing things up
Frequently asked questions
Answers to what we get asked most.
Am I required to apply SII?
It is compulsory for large companies by turnover, VAT groups and REDEME registrants. Any other company may opt in voluntarily. Anyone applying SII does not additionally have to apply Verifactu, because it serves the same reporting purpose.
Which record books are reported?
Issued and received invoices, intra-EU transactions and capital goods, with detail invoice by invoice: tax ID, net amount, rate, tax due and transaction key. It all comes from the invoices already in the system, with no separate files to prepare.
What if the tax authority rejects a record?
The system validates the response and flags records rejected or accepted with errors, along with the description, so they can be corrected and resubmitted within the deadline. Without that control a rejection goes unnoticed and the invoice stays undeclared until a formal request arrives.
How quickly does each invoice have to be reported?
Within a few working days of the invoice being issued or entered into the accounts, depending on the book. Because submissions come automatically from the invoices in the system, the deadline is met without anyone watching the calendar.
Accounting and finance
Invoices post themselves, AEAT tax forms are built from real data and the bank reconciles almost on its own. With Verifactu, TicketBAI and SII solved.
Verifactu
Compliance with the Spanish tax authority's Verifactu regulation: every invoice generates a signed invoicing record chained to the previous one, with its QR code and, if you choose that mode, immediate submission to the tax authority.
View moduleTicketBAI
TicketBAI compliance for invoicing to the Basque regional tax authorities: electronic signature on every invoice, chained records, QR code and submission to the relevant administration.
View moduleBank Reconciliation
Connect to your banks, download transactions without anyone exporting a file, and reconcile them automatically against receipts, payments and accounting entries.
View moduleReceivables and Payables
Every instrument and due date in one place: what is left to collect, what to pay, when each falls due and what state it is in.
View moduleSEPA Remittances
Direct debit collection orders and credit transfer payment orders, generated from outstanding due dates and ready to upload to your bank.
View module