Reference
Markdown exportBT-18 Invoiced object identifier
Identifier of the project, asset, case, or other business object the invoice belongs to.
BT-18 (Invoiced object identifier) links the invoice to a supporting object such as a contract, subscription, or metering point, carried in UBL as an AdditionalDocumentReference with DocumentTypeCode 130. Optional under EN 16931, it typically requires a scheme identifier so the receiver can interpret the reference. Example: CONTRACT-4711.
BT-18 · EN 16931 / XRechnung 3.x
BT Reference Card
Key EN 16931 and XRechnung facts for this business term.
- BT code
BT-18- Name
- Invoiced object identifier
- Cardinality
- Optional (O)
- Business group
- Document
- Data type
- Identifier
- Example value
CONTRACT-4711
Quick answer
Identifier of the project, asset, case, or other business object the invoice belongs to.
Invoice basics
Core document identifiers, dates, process identifiers, and high-level invoice context.
Quick actions
In plain language
Identifier of the project, asset, case, or other business object the invoice belongs to.
Identifier of the project, asset, case, or other business object the invoice belongs to.
Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.
What you usually enter here
Business object identifier
Typical valid values include: PROJECT-7784
Optional according to EN 16931-1.
What goes wrong often
Avoid values like: , AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Examples in context
Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.
Optional according to EN 16931-1.
Valid Examples
- PROJECT-7784
Invalid Examples
- AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
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-18
Data Type:
identifier
Cardinality:
0..1
Requirement:
Optional
Max Length:
50 characters
Since Version:
Optional
XML Implementation
/Invoice/cac:AdditionalDocumentReference[cbc:DocumentTypeCode="130"]/cbc:ID/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeAgreement/ram:AdditionalReferencedDocument/ram:IssuerAssignedIDNext step
Create an XRechnung from your PDF
The converter reads the invoice and shows the fields it found before download, so you can check and correct the values. No PDF? Fill in the XRechnung directly in the form.
Download requires an account. Subscriptions from €10/month with annual billing (excl. taxes), or €5 per conversion (excl. taxes) without a subscription.
Why the standard cares about this field
Business Context
Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.
Legal Requirement
Optional according to EN 16931-1.