VeriFactu Concepts

VeriFactu · Concepts

VeriFactu Concepts

Understanding the core concepts of the VeriFactu system.

Records (Registros)

VeriFactu has three types of records:

Type	Description	Use Case
Alta	Initial registration	New invoice issued
Modificación	Modification	Correct an error
Anulación	Cancellation	Void an invoice

Hash Chain (Cadena de Huellas)

Every VeriFactu record contains a Huella (fingerprint) that cryptographically links to the previous record.

Record 1: Hash(data1) → Huella1
Record 2: Hash(data2 + Huella1) → Huella2
Record 3: Hash(data3 + Huella2) → Huella3

This creates an immutable audit trail.

Digital Signatures

Each record must be signed with:

• X.509 certificate — Issued by a Spanish CAM
• XMLDSig — W3C standard for XML signatures
• RSA-SHA256 — Signature algorithm

AEAT Response

After submission, AEAT returns:

• CSV (Código Seguro de Verificación) — Unique record identifier
• Timestamp — Official registration time
• Status — Aceptado, Rechazado, or Pendiente

Next Steps

• Hash chain deep dive
• Certificate management