Case Study · In Production

XRechnung from abas — in production at a data center operator.

Public-sector and large customers demand XRechnung (the German e-invoicing standard), and the e-invoicing mandate is making compliant formats part of everyday business. telemaxx, a data center and telecommunications operator from Karlsruhe, delivers its outgoing invoices straight from abas as XRechnung and ZUGFeRD — fully automated, validated, audit-proof.

Built for TelemaxX Telekommunikation GmbH, Karlsruhe
Illustration: documents flow cleanly out of abas ERP through the REST interface

The result — every invoice compliant

abas data becomes validated e-invoices. No manual work, no gut feeling.

100 %
validated — KoSIT reference validator
2
formats: XRechnung 3.0 & ZUGFeRD
0
changes to the abas customizing
Straight from abas

Invoice data via REST — without touching the customizing.

Header, line items, customer, tax rates: all invoice data comes through the abas REST API. Nothing about the abas customizing is changed — your ERP stays as it is, and updates stay as simple as they should be.

abas REST API Header & line items Customizing untouched
Compliant formats

XRechnung 3.0 and ZUGFeRD — including the Leitweg-ID.

The output is XRechnung 3.0 as CII XML according to EN 16931, and ZUGFeRD as PDF/A-3 with embedded XML — one document that humans can read and machines can process. The Leitweg-ID, the routing identifier required for delivery to public-sector customers, is carried along.

EN 16931 / CII XML PDF/A-3 with XML Leitweg-ID
Checked twice

What goes out is compliant.

Every invoice passes two independent checks: our own validator (XSD and Schematron) and the KoSIT reference validator — the same instance the recipient side validates against. Only when both give the green light does the invoice leave the building.

XSD + Schematron KoSIT reference validator 100 % checked

Why this holds up in operation

No magic — just craftsmanship.

Illustration: documents flow as a document chain through the REST interface into the ERP

We know abas from the inside.

Invoice header, line items, customer and tax data are read completely via REST — no special tweaks in the ERP and no changes to your customizing.

abas REST 0 customizing changes
Illustration: every invoice is checked against the reference with a magnifying glass

Validated instead of hoped.

Two checks per invoice — our own validator plus the KoSIT reference. An e-invoice that gets rejected on the recipient side simply doesn't happen this way.

Validated twice KoSIT reference
Illustration: processing on a timeline, an error is isolated, analyzed and reprocessed

Replay instead of guesswork.

The raw abas data of every invoice is stored as a “capsule”. If something needs analyzing, we replay the invoice from the capsule — without any access to the live system.

Raw data capsule Analysis without the live system
Illustration: servers and containers run inside your own house, the cloud stays outside

Delivered as a Docker container.

Runs in-house at the customer's site, updates arrive via image pull. No cloud requirement — invoice data stays where it belongs.

On-premise Updates via image pull

What does this mean for you?

This case study is based on our product cayZugferd. What runs in production at telemaxx is not a one-off — it's ready to use for any abas ERP that writes outgoing invoices.

Public-sector customers (XRechnung) Business customers (ZUGFeRD) B2B e-invoicing mandate Leitweg-ID delivery Validation included

Ready for the e-invoicing mandate?

cayZugferd is available as a ready-made product — and if your invoices have a special twist, we'll build it in. Tell us about it.

See cayZugferd