When issuing a CORRECTING invoice via SIGN ES, it is mandatory to specify a correction code that identifies the legal grounds for the correction. These codes correspond to the provisions of Article 80 of the VAT Act (LIVA – Law 37/1992) and are translated internally into keys R1–R4 in the tax XML (Verifactu, TicketBAI or SII).
Key points regarding the corrective invoice
| SIGN ES Code | Key | Reason | Legal basis |
|---|---|---|---|
CORRECTION_1 | R1 | Amount or VAT errors, returns, discounts, rebates, or price changes after the transaction | Art. 80.1, 80.2 and 80.6 LIVA |
CORRECTION_2 | R2 | The recipient has been declared insolvent (bankruptcy) | Art. 80.3 LIVA |
CORRECTION_3 | R3 | The debt is wholly or partially uncollectible | Art. 80.4 LIVA |
CORRECTION_4 | R4 | Any other reason not covered by the above (errors in non-financial data: VAT number, address, description, etc.) | Remaining cases |
Note: In the case of
SIMPLIFIEDinvoices, SIGN ES automatically assigns key R5, regardless of the correction code specified.
When to use each correction code
CORRECTION_1 (R1) – Financial or tax corrections
Used when the correction affects amounts, tax quotas, or fiscally relevant elements of the transaction. This is the most common case.
Typical examples:
- The VAT rate applied was incorrect.
- Goods or packaging are being returned.
- Discounts or rebates granted after the transaction are being applied.
- The agreed price is modified after the transaction.
- The amount was provisional at the time of issue and the final amount is now known.
CORRECTION_2 (R2) – Insolvency proceedings
Used exclusively when the invoice recipient has been declared insolvent and the correction is made for this legal reason.
CORRECTION_3 (R3) – Uncollectible debts
Used when the debt arising from the invoice is wholly or partially uncollectible and the legal requirements to modify the taxable base are met.
CORRECTION_4 (R4) – Remaining cases
Used when the correction does not fit any of the above cases, for example to correct non-monetary data or other aspects not covered by R1, R2, or R3.
Typical examples:
- The recipient's tax identification number was incorrect.
- The address was wrong.
- The description of the transaction contained errors.