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BT-126 Invoice line identifier

A unique identifier for the individual line item within the invoice.

BT-126 (Invoice line identifier) is the per-line index used to reference each invoice line uniquely within the document. Mandatory under EN 16931. Typically a sequential integer ("1", "2", "3"); reused across allowance/charge references. Must be unique within the invoice. Example: 1.

BT-126 · EN 16931 / XRechnung 3.x

BT Reference Card

Key EN 16931 and XRechnung facts for this business term.

BT code
BT-126
Name
Invoice line identifier
Cardinality
Mandatory (M)
Business group
BG-25 INVOICE LINE
Data type
Identifier
Example value
1

Quick answer

A unique identifier for the individual line item within the invoice.

Line items

The goods or services on each invoice line, including quantities, prices, and VAT.

Quick actions

In plain language

A unique identifier for the individual line item within the invoice.

A unique identifier for the individual line item within the invoice.

Essential for referencing and processing individual line items in automated systems.

What you usually enter here

Unique identifier within the invoice, mirroring the original position number

Typical valid values include: 1, 2, 10, 001

Mandatory for each invoice line according to EN 16931-1.

What goes wrong often

Avoid values like: , 0, -1

Relevant rule codes: BR-21

Examples in context

Essential for referencing and processing individual line items in automated systems.

Mandatory for each invoice line according to EN 16931-1.

Valid Examples

  • 1
  • 2
  • 10
  • 001
  • 1.1.30
  • 2.1.40
  • LINE-001

Invalid Examples

  • 0
  • -1

XML mapping and field facts

Open the technical reference if you need XML paths, validator rule codes, legal wording, or schema-specific mapping details.

Field ID:

BT-126

Data Type:

identifier

Cardinality:

1..1

Requirement:

Mandatory

Since Version:

XRechnung 1.0+

XML Implementation

UBL 2.1 Syntax
/Invoice/cac:InvoiceLine/cbc:ID
CII (UN/CEFACT) Syntax
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:LineID

Validation Rules

BR-21

BR-21

Why the standard cares about this field

Business Context

Essential for referencing and processing individual line items in automated systems.

Legal Requirement

Mandatory for each invoice line according to EN 16931-1.

Official sources and tools