Mustang 2.3.0

XRechnung 2.1.1 validation is now possible and a PDF issue has been fixed.

Despite it’s only a minor feature this version is also called 2.3.0 to indicate that the changed (internal) PDF upgrade is also a good opportunity to confirm the output PDF/A validity of at least some random samples 🙂

Screenshot of Quba 0.1

E-Invoice-Viewer Quba 0.1

Some people from the Mustangproject are also involved in the open-source electron based e-invoice viewer “Quba” which released it’s first preview version (“0.1”) today, starting with UN/CEFACT CII support in a version for windows. The announcement has more details and of course the home page has a download button since today.

Mustang 2.1.1

Mustang 2.1.1 fixes

  • recipient contacts in XRechnung
  • remove outdated dependency
  • allow XRechnung without street
  • only deploy library and validator to maven central, not core nor cli
  • a correction should reference the original invoice via invoiceReferencedDocument, not buyerOrderReferencedDocument
  • upgraded CEN Schematron validation (codes 24) to v1.3.4
  • added unit tests for ubl conversion and visualization
  • and adds the possibility to specify a seller order referenced document


Mustang 2.1.0

Mustang 2.1.0 was released on 2021-01-19 and contains

  • The possibility to convert from CII to UBL (thanks to this library)
  • XRechnung now exports as 2.0 (in Mustang 2.0.3 this was automatically switched on 2021-01-01)

Additionally, it

  • fixed a charge/allowance rounding error #212
  • corrected intra community supply tax exemption category code
  • removed Tradeparty.getZip in favor of getZIP (as it’s also setZIP)

Mustang 2.0.3

Mustang 2.0.3 was released on 2020-12-06 and contains minor bugfixes, namely

  • #201 correct embedded files in XRechnung
  • don’t write “null” as paymentDescription if no Bank account is specified
  • generic and unitcode/categorycode improvements (thanks to weclapp-dev) PR #207


  • support credit notes (additionally to corrected invoices)
  • transaction calculator getGrandTotal now public, allowing to compare XML grant total with own calculations
  • programmatically switch to XRechnung 2.0 if invoked after 2021-01-01

Mustang 2.0.2

Mustang 2.0.2 was released on 2020-11-25 and contains minor bugfixes, namely

  • A correction RE file attachments in XRechnung (#197) as well as
  • another category code correction (PR #198 Thanks to weclapp-dev)


  • reverse charge is now supported at all and
  • intra community supply is now also supported in the invoice class

Mustang 2.0.1

Mustang 2.0.1 was released on 2020-11-21 and contains important bugfixes, namely

  • a corrected VAT calculation on prices with >2 decimals
  • the guideline ID for XRechnung has been added (#172)
  • corrected handling of input PDF/A-3 files
  • corrected profile handling of fax-, tax-numbers


  • zero-rated goods are now supported
  • as well as delivery period on item level and
  • the specification of account (holder) names
  • the Factur-X sample has been updated and a XRechnung sample is created in the tests

Mustangproject 2.0 to integrate e-invoice validator

Mustangproject is an open source e-invoicing library and toolkit.
It helps companies to process electronic invoices by providing the functionality to read, write and validate them.

New in version 2

Instead of ZUGFeRD 1, ZUGFeRD version 2 is now the default choice and the library is now available via Maven Central, making it even easier to embed. It’s interface has been enhanced and Mustangproject now supports absolute and relative charges and allowances on item and document level and embedding additional files.

The validator component, which had been developed separately under the project name “ZUV”, has now been merged into
the mainline project and development will be continued there.
It allows the automatic syntactical and arithmetical check of electronic ZUGFeRD 1 and 2 as well as XRechnung 2 invoices.

So far, Mustangproject supported the e-invoice standards Factur-X/ZUGFeRD 2.1, the new release adds support for version 2.1.1 with the
ZUGFeRD “reference profile” XRechnung, as well as a native XRechnung export.

Mustangproject 2.0 will be published on 2020-11-12 between 16:00 and 17:00 CET on it’s Homepage and Maven Central.
Until then, the current alpha-3 prerelease can be tested. Further details of the upcoming release can be obtained from it’s release notes.