Correction codes in SIGN ES: When should CORRECTION_1, CORRECTION_2, CORRECTION_3 and CORRECTION_4 be used?

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Ultimo aggiornamento il 2026-04-14.

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 **SIMPLIFIED**** invoices**, 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.