To correct a previously transmitted e-invoice, issue a credit note using the CORRECTION operation type with data.type = INVOICE. A credit note reverses the amounts of the original invoice — fully or partially. If the original data also needs to be replaced, a new invoice is issued after the credit note.
The credit note always references the original invoice and must be sent to the same recipient.
API usage
INTENTION and TRANSACTION, with an example request.
When to issue a credit note
Cancellation, partial credit, correction or undercharge.
Correction workflows
The flow for each scenario.
Rules
Amounts, references, numbering and entry type.
API usage
Section titled “API usage”INTENTION
Section titled “INTENTION”The INTENTION step follows the same pattern as for a standard invoice. Call the createRecord endpoint with a Record of type INTENTION associated with the E_INVOICE_SERVICE System.
TRANSACTION
Section titled “TRANSACTION”Call the createRecord endpoint with a Record of type TRANSACTION:
- Set the operation type to
CORRECTIONwithdata.type = INVOICE - Reference the original invoice via
operation.record.id - Include the line items being credited (with positive amounts)
- Use the same recipient as the original invoice
Example request — partial credit note
{ "content": { "type": "TRANSACTION", "record": { "id": "<intention-record-id>" }, "operation": { "type": "CORRECTION", "record": { "id": "<original-invoice-transaction-record-id>" }, "data": { "type": "INVOICE", "document": { "number": "CN-2026-000001" }, "entries": [ { "type": "RETURN", "details": { "concept": "GOOD" }, "data": { "type": "ITEM", "text": "White sugar", "unit": { "quantity": "1.00", "price": { "inclusive": "1220.00", "exclusive": "1000.00" } }, "value": { "base": "1000.00" }, "vat": { "type": "VAT_RATE", "code": "STANDARD", "percentage": "22.00", "exclusive": "1000.00", "inclusive": "1220.00", "amount": "220.00" } } } ], "breakdown": [ { "type": "VAT_RATE", "code": "STANDARD", "percentage": "22.00", "exclusive": "1000.00", "inclusive": "1220.00", "amount": "220.00" } ], "totals": { "vat": { "amount": "220.00", "exclusive": "1000.00", "inclusive": "1220.00" } }, "recipients": [ { "type": "BUSINESS", "name": "Dolci Italiani S.r.l.", "identification": { "type": "VAT", "value": "IT12345678901" }, "address": { "street": "Via Roma 1", "city": "Milano", "code": "20121", "region": "MI", "country": "IT" }, "invoicing": { "type": "SDI", "destination_code": "ABC1234" } } ] } } }}Credit notes are created on the E_INVOICE_SERVICE system, following the same INTENTION → TRANSACTION flow as for e-invoices.
When to issue a credit note
Section titled “When to issue a credit note”| Scenario | Action | Documents issued |
|---|---|---|
| Full cancellation — duplicate, wrong buyer, or cancelled transaction | Credit the full amount | Credit note only |
| Partial credit — return, discount, or overbilling | Credit the affected lines or amounts only | Credit note only |
| Correction — wrong data or amounts on the original invoice | Credit the full amount, then re-issue corrected | Credit note + new invoice |
| Undercharge — original amount was too low | Credit the full amount, then re-issue with the correct amount | Credit note + new invoice |
Correction workflows
Section titled “Correction workflows”Full cancellation
Section titled “Full cancellation”Use when the original invoice should never have been issued (duplicate, wrong buyer, cancelled order).
Original Invoice INV-001 €6300.00 ↓Credit Note CN-001 €6300.00 (references INV-001) ↓Net result: €0.00The original invoice remains on record. The credit note creates a full reversal.
Partial credit
Section titled “Partial credit”Use when only part of the original invoice needs to be reversed (returned item, agreed discount, overbilling on specific lines).
Original Invoice INV-001 €6300.00 ↓Credit Note CN-002 €600.00 (references INV-001, affected lines only) ↓Net result: €5700.00Only the credited lines are included in the credit note. The original invoice remains valid for all non-credited lines.
Correction (credit + re-issue)
Section titled “Correction (credit + re-issue)”Use when the original invoice contained incorrect data or amounts.
Original Invoice INV-001 €6300.00 ↓Credit Note CN-003 €6300.00 (full reversal, references INV-001) ↓New Invoice INV-002 €5950.00 (corrected data) ↓Net result: €5950.00Fully reverse the original via a credit note, then issue a new invoice with the correct data.
Undercharge (credit + re-issue higher)
Section titled “Undercharge (credit + re-issue higher)”Use when the original invoice amount was too low.
Original Invoice INV-001 €5000.00 ↓Credit Note CN-004 €5000.00 (full reversal, references INV-001) ↓New Invoice INV-003 €6300.00 (correct amount) ↓Net result: €6300.00Credit note + re-issue
Section titled “Credit note + re-issue”For correction and undercharge scenarios, two separate transactions are needed:
- Create a
CORRECTIONrecord (credit note) referencing the original invoice - Create a new
INVOICErecord with the corrected data
Both records follow the standard INTENTION → TRANSACTION flow.
Amounts must be positive
Section titled “Amounts must be positive”All amounts on a credit note are required to be positive. The document type signals that positive line amounts represent credits. Negative values will cause validation failures. Always issue a credit note as a CORRECTION. An INVOICE with negative amounts isn’t a credit note.
Preceding document reference is required
Section titled “Preceding document reference is required”Every credit note references the original invoice. In the CORRECTION::INVOICE request, provide the ID of the original transaction record in the content.operation.record.id field. fiskaly resolves the preceding document details automatically.
{ "content": { "type": "TRANSACTION", "record": { "id": "<intention-record-id>" }, "operation": { "type": "CORRECTION", "record": { "id": "<original-transaction-record-id>" }, "data": { "type": "INVOICE", ... } } }}Recipient must match
Section titled “Recipient must match”Use the same recipient as on the original invoice, with the same delivery channel and format.
Separate numbering series
Section titled “Separate numbering series”Credit notes must use a separate sequential numbering series (e.g. CN-2026-000001). Include the series prefix in document.number and leave document.series unset.
Entry type
Section titled “Entry type”You don’t set the document type: it is derived from the Unified API operation you call. A CORRECTION produces a credit note and an INVOICE produces an invoice, whatever the entry type.
Set entries[].type = RETURN on each credited line, with positive amounts. The lines on the original invoice use SALE.
To charge for new items, issue a separate invoice.
Line fields you do not need to match
Section titled “Line fields you do not need to match”Two fields in entries[] commonly cause unnecessary work on a credit note:
entries[].details.numberis not used in e-invoicing. It exists for the fiscalization products, where it identifies the original line being corrected. You do not map original line numbers onto a credit note — the link to the original invoice is made once, at document level, throughoperation.record.id.entries[].data.textis not validated and does not have to repeat the wording used on the original invoice.
One invoice, several credit notes
Section titled “One invoice, several credit notes”Several credit notes may reference the same original invoice — for example when goods from a single invoice are returned in separate batches, or when different lines are credited at different times. Each one is an independent CORRECTION record carrying the same operation.record.id and containing only the lines it credits. The original invoice stays valid for the lines that have not been credited. Make sure the credit notes on one invoice don’t add up to more than the invoice. A credit note that has been reversed by a new invoice no longer counts towards this total.
A credit note is never credited
Section titled “A credit note is never credited”A credit note always references an invoice, never another credit note. If a credit note itself needs correcting, issue a new document instead. Which one depends on what was wrong:
| What was wrong | Action | Documents issued |
|---|---|---|
| Too little credited | Credit the missing amount | Another credit note, referencing the original invoice |
| Too much credited, or issued by mistake | Invoice the difference | New invoice, referencing the credit note |
| Wrong data on the credit note | Invoice the credit note amount, then credit again correctly | New invoice referencing the credit note + new credit note referencing the original invoice |
Too little credited
Section titled “Too little credited”Original Invoice INV-001 €6300.00 ↓Credit Note CN-001 €300.00 (references INV-001, should have been €600.00) ↓Credit Note CN-002 €300.00 (references INV-001, the missing amount) ↓Net result: €5700.00Too much credited, or issued by mistake
Section titled “Too much credited, or issued by mistake”Original Invoice INV-001 €6300.00 ↓Credit Note CN-001 €6300.00 (references INV-001, should have been €600.00) ↓New Invoice INV-002 €5700.00 (references CN-001, the difference) ↓Net result: €5700.00For a credit note issued by mistake, the new invoice is for the full credit note amount.
Wrong data on the credit note
Section titled “Wrong data on the credit note”Original Invoice INV-001 €6300.00 ↓Credit Note CN-001 €600.00 (references INV-001, wrong data) ↓New Invoice INV-002 €600.00 (references CN-001, reverses it) ↓Credit Note CN-002 €600.00 (references INV-001, correct data) ↓Net result: €5700.00The new invoice carries the number and issue date of the credit note it reverses in document.references.preceding_document.
Crediting an invoice fiskaly did not transmit
Section titled “Crediting an invoice fiskaly did not transmit”The document type is derived from the operation rather than set by you: a CORRECTION produces a credit note, an INVOICE produces an invoice. Referencing an externally issued invoice as the preceding document on an INVOICE operation will transmit successfully, but the document carries the invoice type — which increases the amount owed instead of cancelling it.
If you are migrating to fiskaly, keep your previous e-invoicing system available until every invoice it issued has been settled or credited. Where a one-off correction is unavoidable, some tax authorities let a merchant issue a credit note manually, outside their provider — availability and process differ by country, so check the country page for yours.