Spain B2B e-invoicing from 6 October 2027: what invoicing software must ship

If you build invoicing, ERP or accounting software with Spanish customers, the waiting is over: Order HAC/1028/2026 entered into force on 6 October 2026, which fixes the B2B e-invoicing dates in Royal Decree 238/2026. Businesses with more than EUR 8 million volume of operations start on 6 October 2027, everyone else on 6 October 2028. Here is what that means for your product.

The dates

Date	What changes
6 Oct 2026	Order HAC/1028/2026 in force; the 12- and 24-month clocks start.
By early Aug 2027	The AEAT's public e-invoicing solution must be available (at least two months before it first applies).
6 Oct 2027	Issuers above EUR 8 million must issue and receive B2B e-invoices. Private platforms must send faithful copies to the AEAT and interconnect.
6 Oct 2027 – 5 Oct 2028	Those large issuers also send a readable PDF with each e-invoice, unless the buyer accepts the XML alone.
6 Oct 2028	Everyone else, including the self-employed.
6 Oct 2029	Status reporting becomes mandatory for individuals and income-attribution entities up to EUR 8 million.

Scope: invoices to businesses and professionals established in Spain. Simplified invoices are out unless they are qualified simplified invoices.

Formats

• EN 16931 in UBL, CII, EDIFACT or Facturae. Peppol BIS is accepted on private platforms.
• The AEAT's public solution uses UBL only, with Spanish fields (copy indicator, payment date, withholdings, VERI*FACTU / TicketBAI QR reference) and no embedded files.
• Invoices through private platforms need an advanced electronic signature.
• Each invoice has a unique code: issuer NIF + series and number + issue date.

The faithful copy

If an invoice does not go through the public solution, the system that issues it must send the AEAT a faithful copy in UBL at the moment of issue, flagged with cbc:CopyIndicator = true. The AEAT validates it; a rejected copy must be fixed and resent, and duplicates are rejected.

Status and payment reporting

Buyers report acceptance or rejection and full payment (with dates) to the issuer, and full payment or rejection plus the due date to the AEAT, within four days excluding weekends and national holidays. No rejection means the invoice is presumed accepted.

VERI*FACTU

Separate regime. Legal dates are 1 January 2027 (corporate taxpayers) and 1 July 2027 (others); on 5 October 2026 the Ministry of Finance announced a move to October 2028, which still needs a new legal text.

Checklist for builders

• Segment users by the EUR 8 million threshold.
• Emit EN 16931 UBL (it is what the AEAT and the copy use).
• Decide: integrate the AEAT public solution yourself or connect a private platform.
• Add Spanish fields: copy indicator, IRPF withholdings, corrective-invoice codes, VERI*FACTU / TicketBAI reference.
• Enforce unique invoice numbers per series before anything reaches the AEAT.
• PDF companion for large issuers in year one.
• Record and report acceptance, rejection and payment within four working days.
• Validate against EN 16931 before sending.

Try it with an API

Disclosure: I build W System, the API used here. POST https://api.wsystem.dev/einvoice/create with "format": "peppol-bis3" and Spanish parties returns an EN 16931 UBL invoice checked against EN 16931. It does not add the Spanish BT-ES fields, sign, or send anything to the AEAT; use it to test your EN 16931 output, or drop a file into the free validator at wsystem.dev/e-invoice-validator. Full article with sources (BOE texts) and the live response: https://wsystem.dev/spain-b2b-e-invoicing-2027-software

Not tax advice.