BT-24

Also called specification identifier, guideline identifier, Specification identifier BT-24

BT-24 is the specification identifier: a URN inside the XML declaring which ruleset the invoice claims to follow. It is what a receiving system reads first, because it determines which rules apply, and it is how a CIUS such as XRechnung announces itself.

Business term: BT-24
Name: Specification identifier
Form: A URN, e.g. urn:cen.eu:en16931:2017
Required?: Yes. Its absence is BR-01

One field that changes how everything else is judged

The value is a URN. An EN 16931 CII invoice carries urn:cen.eu:en16931:2017, with a further extension appended for a CIUS or a Factur-X profile.

Get it wrong and you get an oddly shaped failure: the invoice is validated against rules it was never built for, so the findings look unrelated to the actual problem.

Why we read it back rather than trusting it

Our generator derives the conformance level by reading BT-24 out of the XML it just built, rather than taking the profile from the request. That looks redundant and is not.

Gotenberg will stamp a MINIMUM XMP onto EN 16931 XML without complaint. The file opens fine, disagrees with itself, and our own public validator reports it. Shipping that from the generator would be an embarrassing thing to do, given we built the detector.

Why it matters

It decides which ruleset your invoice is judged against, so an incorrect value produces failures that look like they belong to a different document.
It is how you discover, without reading the whole file, that a supplier is sending you a CIUS you have not implemented.

Check it on your own file

Read BT-24 from a file
Shown in the report, and compared against the profile the PDF metadata claims.
BR-01, when it is missing
The rule that fires when BT-24 is absent, with the fix.

Common questions

What is the specification identifier in an e-invoice?: BT-24, a URN declaring which ruleset the invoice follows. Receiving systems read it first to decide which validation rules apply.