BR-16: Invoice Has No Invoice Line, the EN 16931 Rule Explained

What BR-16 checks

BR-16 requires that an invoice contain at least one invoice line, BG-25: cac:InvoiceLine in UBL, ram:IncludedSupplyChainTradeLineItem in CII. The European core model is line-based by construction: totals are derived from lines, VAT is broken down from lines, and buyer-side automation matches lines against orders. A document that only states "Amount due: 1,190.00 EUR" may be a perfectly good letter, but it cannot be an EN 16931 invoice.

Layer and formats

BR-16 lives in the en16931 core layer and applies to every syntax and every profile claiming core compliance. The only e-invoice documents legitimately without lines are the Factur-X / ZUGFeRD MINIMUM and BASIC WL profiles, which sit below the core and declare so in BT-24.

Why it fails in practice

Summary exports. The source system holds positions, but the e-invoice export was modelled on the PDF cover sheet and emits only header and totals.
A profile mismatch. A pipeline built for ZUGFeRD BASIC WL is switched to an EN 16931 profile, and the lineless documents it produces start failing.
Filtering gone wrong. Zero-amount or fully discounted positions are dropped by an export filter, and for some documents nothing is left.

How to fix it

Emit at least one complete line. A minimal UBL line:

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cbc:InvoicedQuantity unitCode="C62">1</cbc:InvoicedQuantity>
  <cbc:LineExtensionAmount currencyID="EUR">1000.00</cbc:LineExtensionAmount>
  <cac:Item>
    <cbc:Name>Consulting services March</cbc:Name>
    ...
  </cac:Item>
  <cac:Price><cbc:PriceAmount currencyID="EUR">1000.00</cbc:PriceAmount></cac:Price>
</cac:InvoiceLine>

In an InvoiceXML create request the lines are the invoice.lines array; one entry with name, quantity, unit and price is enough, and the request is rejected up front with a clear model error if the array is empty.

The raw rejection vs the InvoiceXML finding

The Schematron report:

<svrl:failed-assert id="BR-16" flag="fatal"
    location="/*:Invoice[namespace-uri()='urn:oasis:names:specification:ubl:schema:xsd:Invoice-2'][1]">
  <svrl:text>[BR-16]-An Invoice shall have at least one
    Invoice line (BG-25)</svrl:text>
</svrl:failed-assert>

The InvoiceXML finding for the same failure:

{
  "rule": "BR-16",
  "layer": "en16931",
  "line": null,
  "message": "An invoice must have at least one line item. Add at least one invoice line.",
  "btCodes": ["BG-25"],
  "fields": ["lines"],
  "raw": "[BR-16] EN16931: An Invoice shall have at least one Invoice line (BG-25)"
}

The message is end-user ready and fields points at the request property to fix. For line-scoped rules the mapping goes further: the finding carries the 1-based line number and the path includes the concrete index, for example lines[3].vatInformation.rate, so your UI can highlight the exact row. Clients wanting their own wording localize by the stable rule key.

Check or generate compliant documents

Validate a suspect file in the UBL validator or the XRechnung validator. Generating through POST /v1/create/ubl or POST /v1/create/facturx turns BR-16 into a simple request-shape question: no empty lines array ever becomes XML. The core model behind the rule is covered in EN 16931 explained.

BR-01, the sibling core rule requiring a specification identifier
BR-CO-10, the totals rule summing exactly these lines
urn:factur-x.eu:1p0:minimum and urn:factur-x.eu:1p0:basicwl, the two profiles that legitimately omit lines

Frequently asked questions

Can I send an invoice with just a total and no lines?

Not as an EN 16931 compliant document. The core model requires at least one line with its own identifier, quantity, unit, net amount and item name. If your business case is a single lump sum, model it as one line covering the whole delivery.

Are there formats where lines are optional?

The Factur-X / ZUGFeRD MINIMUM and BASIC WL profiles carry no lines by design, but they are below the EN 16931 core and do not claim compliance with it. Every profile that does claim compliance, from the core itself through XRechnung and Peppol BIS, inherits BR-16.

What does one valid line minimally contain?

The core's line-level rules require an identifier (BT-126), a quantity (BT-129) with a unit (BT-130), a net amount (BT-131), an item name (BT-153), a net price (BT-146) and a VAT category. A line missing those trips the BR-21 to BR-27 family next.

In which layer does BR-16 fire?

In the en16931 core layer, for every format and profile: UBL, CII, XRechnung, Peppol BIS and EN 16931 compliant hybrids all reject a line-less invoice.

BR-16