Verifactu and SII: differences, who is obliged and why they do not add up

What the SII is: VAT books kept on the AEAT portal

The SII (Suministro Inmediato de Información) is not a program or an invoice format: it is a way of keeping the libros registro de IVA (VAT record books; IVA is Spanish VAT). It is governed by article 62.6 of the VAT Regulation (Royal Decree 1624/1992): whoever is in the SII keeps their books "through the electronic office of the Agencia Estatal de Administración Tributaria (AEAT), by electronically supplying the invoicing records".

It covers the four books of article 62.1:

• Issued invoices.
• Received invoices.
• Investment goods.
• Certain intra-Community transactions.

What makes it demanding are the deadlines of article 69 bis. Issued invoices are reported within four calendar days of being issued (eight if the invoice is issued by the recipient or a third party) and, in any case, before the 16th of the month following the date the tax becomes chargeable. Received invoices are reported within four days of being entered in the accounts and before the 16th of the month following the filing period in which they are included. Saturdays, Sundays and national public holidays are excluded when counting those days, so in practice it means four working days.

Outside the SII, article 69 only requires transactions to be recorded by the time you settle the tax. If you want to review which books a regular autónomo keeps, see the guide on the self-employed VAT books.

Who must use the SII and who joins voluntarily

Article 62.6 does not give its own list: it obliges to join the SII anyone with "a filing period that coincides with the calendar month" under article 71.3 of the VAT Regulation. They settle VAT monthly, and therefore go to the SII:

• Large companies: anyone whose volume of operations exceeded 6,010,121.04 euros (article 121 of the VAT Law) in the previous calendar year, or who exceeds that figure by adding the business acquired from another trader.
• REDEME registrants: those authorised to request monthly VAT refunds (article 30 of the Regulation), even if nothing is due back to them.
• VAT groups: entities that apply the special regime for groups of entities.
• Fuel tax warehouses: their holders and those who withdraw petrol, diesel or biofuels from them.

Any other trader or professional can opt for the SII. Article 68 bis sets the conditions: the option is exercised at any time of the year with the census return, takes effect in the next filing period, renews itself every year and binds you to stay for at least the whole calendar year in which it is exercised. Withdrawal is filed in November for the following year.

A typical autónomo or small SL falls under none of the mandatory cases. If that is you, you are not in the SII unless you asked for it.

Why anyone in the SII is outside Verifactu

Article 3.3 of Royal Decree 1007/2023, the Verifactu regulation, says it in one sentence: "This Regulation shall not apply to taxpayers who keep the record books under the terms laid down in paragraph 6 of article 62 of the Value Added Tax Regulation".

The logic is simple. Verifactu exists so that the AEAT can trust that no invoice has been deleted or altered: the program generates a chained registro de facturación (invoicing record) with a hash and puts a QR code on every invoice. Anyone in the SII already hands every invoice, issued and received, to the tax agency within four working days. Also requiring the Verifactu chain would duplicate the control.

Three consequences worth being clear about:

• The exclusion does not distinguish between mandatory and voluntary users. Article 3.3 refers to anyone who keeps the books through the SII, nothing more. Our guide on the Verifactu postponement records it the same way.
• Your invoices must not carry the Verifactu QR. If you move to the SII, your program has to stop printing it, as the AEAT recalls in its frequently asked questions on the scope of application.
• The exclusion lasts as long as the SII does. If you leave the SII, you come back within the scope of Verifactu and your program must comply from that moment.

Verifactu vs SII: the differences in a table

Both systems pursue the same goal, that sales cannot be hidden, but they work very differently:

The Verifactu dates and penalties are covered in what is Verifactu. The SII penalty is the one in article 200 of the Ley General Tributaria (General Tax Law), which classes as a serious infringement "the delay in the obligation to keep the Record Books through the electronic office". A basic difference: in Verifactu what is punished is the program; in the SII, each delay.

A small SL joining the SII voluntarily

This is the most repeated question: if I join the SII, do I get out of Verifactu? Yes, under article 3.3. But look at what you take on in exchange, because the SII is more demanding than Verifactu for a small company.

1. How you join. With the census return, at any time of the year. The option takes effect in the next filing period and binds you to stay for at least the whole calendar year (article 68 bis). Leaving requires withdrawing in November for the following year.
2. What changes every week. Each issued invoice and each received invoice is reported within four working days. That requires booking expenses almost daily, not when the quarter closes.
3. What does not change. Your VAT filing period. Article 71.3 only switches the obliged members to monthly, not the voluntary ones, so you keep filing the modelo 303 (the quarterly VAT return) every quarter.
4. What you gain. You are out of Verifactu and of two informative returns, even if you join voluntarily: the modelo 347, because article 32, letter e), of Royal Decree 1065/2007 excludes everyone obliged under article 62.6 of the VAT Regulation; and the modelo 390, because article 71.1 of the VAT Regulation, with its implementing order, exempts those who already give the AEAT "sufficient information".
5. What you risk. The late-filing penalty of article 200 LGT: 0.5% of each invoice sent late, with a minimum of 300 euros per quarter. A bad holiday month without sending records costs money.

In practice, joining the SII just to dodge Verifactu rarely pays off for a small SL: you will need the adapted invoicing program anyway, and the SII adds a permanent weekly workload. Talk it over with your adviser before filing the census return, and keep in mind that the SII does not take you out of B2B electronic invoicing, which is a different obligation.

TicketBAI, the Basque Country and Navarre: another league

Verifactu and the SII are rules for the common territory. Article 1.3 of RD 1007/2023 limits Verifactu to those with their tax domicile in the common territory, without prejudice to the foral regimes.

• In Álava, Bizkaia and Gipuzkoa, TicketBAI applies, with the rules of each foral tax authority.
• Navarre has its own foral rules.

If your tax domicile is in one of those territories, neither this table nor the Verifactu dates are yours: check the rules of your foral tax authority.

What to do depending on your case

• Autónomo who settles VAT quarterly: you are not in the SII. Your date is Verifactu, 1 July 2027; the detail is in Verifactu for autónomos.
• Small SL without the SII: your invoicing program must be adapted to Verifactu before 1 January 2027. You do not need the SII for anything.
• Company already in the SII: carry on as you are. Verifactu does not apply to you and your invoices carry no Verifactu QR. Just make sure that, if you leave the SII, your program starts complying with Verifactu that same day.
• Company that crosses 6,010,121.04 euros: the following year you switch to monthly settlement and enter the SII, and with that you leave Verifactu. Prepare the change in good time, because it also changes your filing calendar.
• You are considering joining voluntarily: weigh the weekly workload and the risk of penalties against what you save, and decide with your adviser.

To fit these dates with your other obligations, see the 2026-2027 tax calendar.

Frequently asked questions

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