Guides

Negative Lines

How to create negative invoice lines for corrections and adjustments in EN16931-compliant invoices.

When to Use Negative Invoice Lines

Negative invoice lines are used when you need to subtract an amount from the invoice total as a line item within an otherwise positive invoice. Common use cases include:

Partial returns within a new order – A customer returns some items while ordering new ones
Price adjustments on an active invoice – A correction alongside other billable items
Goodwill gestures combined with new charges – A credit line on an invoice with positive lines

Do not use negative lines for allowances! If you want to apply a discount, rebate, or allowance to your invoice, use the dedicated allowances fields instead. Negative lines should only be used for actual line-item corrections.

Do not use negative lines instead of credit notes! If you need to fully or partially reverse a previous invoice, issue a proper Credit Note (invoice type code 381) instead. Credit notes are the correct document type for:

Cancelling an entire invoice
Issuing a refund for returned goods
Correcting a previously issued invoice

Negative lines are only appropriate when the negative amount is part of a new invoice that also contains positive charges.

How It Works

A negative invoice line works just like a regular line, but with a negative quantity or negative net amount:

Field	Positive Line	Negative Line
`invoiced_quantity`	`100`	`-1`
`invoice_line_net_amount`	`2145`	`-100`
`item_net_price`	`21.45`	`100` (always positive)

The item_net_price should always be positive. Use a negative invoiced_quantity to achieve a negative line total.

Example

Here's an invoice with two lines: a regular positive line and a negative credit line.

negative-line-example.json

{
    "invoice_number": "33445566",
    "invoice_issue_date": "2019-08-24",
    "invoice_type_code": 380,
    "invoice_currency_code": "EUR",
    "buyer_reference": "abs1234",
    "payment_terms": "#SKONTO#TAGE=14#PROZENT=2.25#",
    "delivery_information": {
        "actual_delivery_date": "2025-10-10"
    },
    "additional_supporting_documents": [
    {
        "supporting_document_reference": "123",
        "supporting_document_description": "Something"
    }],
    "seller": {
        "name": "Full Formal Seller Name LTD.",
        "vat_identifier": "DE-123",
        "identifier": [
            {
                "scheme_identifier": "0094",
                "value": "Full Formal Seller Name LTD."
            }
        ],
        "electronic_address": {
            "value": "DE123456789",
            "scheme_identifier": "9930"
        },
        "postal_address": {
            "city": "Sun City",
            "post_code": "12345",
            "country_code": "AD"
        },
        "contact": {
            "point": "Jens Jensen",
            "telephone_number": "876 654 321",
            "email_address": "jens.j@buyer.se"
        }
    },
    "buyer": {
        "name": "Buyer Full Name AS",
        "electronic_address": {
            "value": "DE987654321",
            "scheme_identifier": "9930"
        },
        "postal_address": {
            "city": "Moon City",
            "post_code": "12345",
            "country_code": "AD"
        }
    },
    "payment_instructions": {
        "payment_means_type_code": "30",
        "credit_transfer": [
            {
                "payment_account_identifier": "NO99991122222"
            }
        ]
    },
    "document_totals": {
        "sum_of_invoice_line_net_amount": 2045,
        "invoice_total_amount_without_vat": 2045,
        "invoice_total_amount_with_vat": 2556.25,
        "invoice_total_vat_amount": 511.25,
        "amount_due_for_payment": 2556.25
    },
    "vat_breakdown": [
        {
            "vat_category_taxable_amount": 2045,
            "vat_category_tax_amount": 511.25,
            "vat_category_code": "S",
            "vat_category_rate": 25
        }
    ],
    "invoice_line": [
        {
            "invoice_line_identifier": "12",
            "invoiced_quantity": 100,
            "invoiced_quantity_unit_of_measure_code": "Lizenzen",
            "invoice_line_net_amount": 2145,
            "price_details": {
                "item_net_price": 21.45,
                "item_price_discount": 100,
                "item_gross_price": 121.45
            },
            "line_vat_information": {
                "invoiced_item_vat_category_code": "S",
                "invoiced_item_vat_rate": 25
            },
            "item_information": {
                "name": "Item name"
            }
        },
        {
            "invoice_line_identifier": "13",
            "invoiced_quantity": -1,
            "invoiced_quantity_unit_of_measure_code": "Lizenzen",
            "invoice_line_net_amount": -100,
            "price_details": {
                "item_net_price": 100
            },
            "line_vat_information": {
                "invoiced_item_vat_category_code": "S",
                "invoiced_item_vat_rate": 25
            },
            "item_information": {
                "name": "Item name"
            }
        }
    ],
    "validation_mode": "lax"
}

Breaking Down the Example

Line 1 (Positive):

Quantity: 100 licenses
Net price per unit: 21.45 €
Line net amount: 2145 € (100 × 21.45)

Line 2 (Negative Credit):

Quantity: -1 (negative!)
Net price per unit: 100 € (positive)
Line net amount: -100 € (−1 × 100)

Totals:

Sum of line net amounts: 2145 + (−100) = 2045 €
VAT (25%): 511.25 €
Invoice total with VAT: 2556.25 €

Negative Lines vs. Allowances vs. Credit Notes

Use Case	Solution
General discount (e.g., 10% off)	Use `allowances` at document or line level
Promotional rebate	Use `allowances`
Early payment discount (Skonto)	Use `payment_terms` with skonto info
Cancelling a previous invoice	Issue a Credit Note (type `381`)
Full refund for returned goods	Issue a Credit Note (type `381`)
Correcting a past billing error	Issue a Credit Note (type `381`)
Return of items on a new order	Use negative invoice line
Price adjustment on a new invoice	Use negative invoice line
Goodwill credit combined with new charges	Use negative invoice line

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