e-Invoicing in Spain: Ley 18/2022 explained

What the invoice contains

Invoices must be structured data in one of four formats aligned with the EN 16931 standard: UBL, CII, EDIFACT or Facturae. The public solution uses UBL. Platforms must convert between the permitted formats and sign invoices with an advanced electronic signature. Each invoice carries a unique code built from the issuer's tax ID, series, number and issue date. Private platforms must send a faithful UBL copy of every invoice to the public solution, and the public solution validates submissions and can reject them.

What your ERP has to deliver

Finance systems must create EN 16931 compliant UBL (or another permitted format) and connect to a private platform or to the AEAT public solution by web form or web service. They must also handle status messages: the buyer has to report acceptance or rejection and full payment within 4 natural days, excluding weekends and national holidays, and the payment due date has to be known. Access to the public solution uses an electronic certificate, so signing and representation rights need to be set up. For the first 12 months after an issuer's start date, larger businesses must also send a readable PDF unless the buyer accepts the original format.

Practical insights

• The Spanish system is not a pure clearance model. Companies may keep using private platforms, but a copy of each invoice and the payment status must reach the public solution. Companies need a plan for both channels.
• The start dates run from 6 Oct 2026 and are based on the previous calendar year's turnover. A group with several Spanish entities can have entities starting in 2027 and others in 2028, so each entity should be checked separately.
• Payment reporting is new for most finance teams. The buyer must record commercial acceptance or rejection and the effective payment date, and an invoice with no rejection is presumed accepted. Accounts payable processes need to produce these events in good time.
• Spain also has separate invoicing-system rules (VERI*FACTU) and immediate VAT reporting (SII). These apply to different data and different dates, so they should be planned as separate workstreams.

Common pitfalls

• Assuming the October 2027 date applies to everyone. Only businesses above EUR 8 million turnover in the previous year start then; most others start in October 2028.
• Treating a PDF or a scanned image as an e-invoice. Only structured formats count, and the PDF is only a transitional extra for larger issuers.
• Ignoring the buyer-side duties. Recipients must report rejection and payment within 4 natural days (weekends and holidays excluded), and many AP processes cannot send this data yet.
• Mixing up the three regimes. B2G invoices to public bodies use FACe, B2B e-Invoicing uses the new system, and SII is a separate VAT reporting obligation.