In 2025 the technical regulation for certified invoicing was finalised and the AEAT's Verifactu services went live. The mandatory use deadlines rolled into 2026: January for companies subject to Corporate Income Tax, July for the self-employed and others. This guide explains what changed, who is affected, and what you need to do now. It covers QR codes, hash chains, event logs, SII, and Crea y Crece, with exact dates. See also the complete electronic invoice guide for full context.
What changed in 2025? The AEAT launched Verifactu services for testing and pilots. The technical specifications were finalised: QR code, hash chain, record formats, etc. Mandatory use obligations started in 2026.
When do the obligations start? Companies subject to Corporate Income Tax are obligated from 1 January 2026. The self-employed and others from 1 July 2026.
What is SII? The Immediate Information Supply system is where certain taxpayers send their VAT sales and purchase books to the AEAT within a few days. It is not electronic invoicing or Verifactu.
Is SII mandatory for everyone? No. SII only applies to monthly VAT filers: Large Companies, REDEME, and VAT groups. It is voluntary for others.
How does Crea y Crece relate to Verifactu? They are separate things. Verifactu regulates anti-fraud controls and the QR code. Crea y Crece will require B2B electronic invoices once its regulation is approved.
Is there a free option? Yes. You can comply at zero cost with a free plan from a compatible tool. renn offers free invoicing with Verifactu support.
The AEAT activated Verifactu services in April 2025 so software providers and companies could test submissions, queries, and QR verification.
User deadlines moved to 2026. Software manufacturers kept their 2025 milestones.
Final technical specifications: QR code size and content, hash chain, event log formats, export and multi-entity use — all defined.
SII scope did not change: it remains for monthly VAT filers only.
The Crea y Crece B2B e-invoice will roll out in phases after its regulation is approved, with staggered timelines by company size.
Active AEAT services: you can submit invoicing records, query what was submitted, and allow recipients to verify invoices via QR code.
Companies with Corporate Income Tax: mandatory from 1 January 2026. If they invoice under CIT and have not yet updated their software, they are already out of compliance.
Self-employed and others: deadline is 1 July 2026. Few months left. Use this time to complete the technical integration.
Software manufacturer obligations in force: only buy tools whose manufacturers have signed the compliance declaration.
In 2025 it was voluntary. Use of Verifactu was optional throughout the year. 2025 was the year to prepare and integrate software.
B2G e-invoicing as always: invoices to public administrations have been covered since 2015. Nothing new there.
From 2026: companies with CIT from 1 January. Self-employed and others from 1 July. The obligation is already active for a large part of the business community.
Crea y Crece B2B: when the regulation is approved, companies with more than 8 million euros in turnover will have 1 year. Others will have 2 years, with additional time for SMEs and the self-employed to report invoice statuses.
QR code: a square readable by phone. Print it at 3 to 4 cm wide (30-40 mm). Use standard QR with level M so it reads even if partially damaged. If your invoice is fully electronic, you can embed the QR URL instead of a printed square.
Mandatory labels: when operating in VERI*FACTU mode (real-time submission), add the Verifactu label and the unique code so the recipient knows how to verify.
Hash chain: the hash is the digital fingerprint of the data. Each record links to the next. If someone modifies a record afterwards, the chain breaks and the system alerts.
Event log: internal diary of key actions: anomalies, exports, and switches between VERIFACTU and NO VERIFACTU modes.
Export and retention: keep data readable and unaltered. Export the complete period when required and keep a faithful copy.
Recipient visibility: provide free access to your clients' e-invoices for 4 years. During the coexistence period, attach a readable PDF if needed.
Learn more about electronic invoicing here.
Who must use SII: Large Companies (6 million euros or more in transaction volume), REDEME, and VAT groups. Submission deadline of 4 days, or 8 if it is a self-invoice or issued by a third party.
Optional for others: you can join SII using Form 036. Once in, you stay for the full year.
Do not mix the regimes: SII is VAT books. Verifactu is certified invoicing with QR. Crea y Crece is B2B e-invoicing. Plan each one separately.
What is operational: submission services, query portal, downloads, and QR verification for recipients.
Why act now: companies with CIT are already obligated. The self-employed have until July. Every week without updated software is a sanctions risk.
Common mistake: confusing mandatory SII with Verifactu. They are separate systems with separate obligations. Read our guide on what Verifactu is and when it is mandatory to be clear.
2025 was the year to prepare. 2026 is the year to comply. Companies with CIT have been obligated since January. The self-employed have until July. Build QR codes, hash chains, event logs, and AEAT connectivity now to avoid being late. Keep the differences between SII, Verifactu, and Crea y Crece clear: they are three separate systems with separate timelines. For more detail, see our guide: Verifactu: what it is and when it is mandatory. If you want to start now, use renn's free invoicing and comply on time without surprises.
