Pricing
What a commercial Klarfakt licence costs, what it covers, and the rule pack update commitment.
Most people reading this owe nothing. Klarfakt is free unless your organisation turns over more than €1,000,000 a year, free at any size inside OSI-licensed open source, and free always for evaluation, development, CI and internal testing.
If that covers you, stop here and go back to the README.
Commercial licence
For production use above that threshold. Per organisation per year, excluding VAT where applicable.
| Standard | Extended | |
|---|---|---|
| €690 / year | €1,900 / year | |
| Developers | unlimited | unlimited |
| Deployments | unlimited | unlimited |
| Validations | unlimited | unlimited |
| Rule pack updates | for the term | for the term |
| Support | email, usually within two working days | one working day, Monday to Friday |
| A named contact, and your issues looked at ahead of the backlog | ||
| Suited to | using Klarfakt inside your own systems | shipping it inside a product you sell |
No metering, ever. Validation happens in your process, on your hardware. Klarfakt cannot count your invoices and is not built to.
What a licence keeps
A licence covers every version released during its term, permanently. Licence today, stop renewing in a year, and you keep the right to run everything published in that year, in production, indefinitely. What lapses is new versions and support, not the software already in your pipeline.
That matters more than usual here, because Klarfakt is maintained by one person. You should not have to bet an invoice pipeline on anyone’s continued attention.
Founding customers
The first three commercial licences are €390 a year, held at that price for three years, in exchange for permission to name the customer and an honest conversation about what is missing. Three people saying what is wrong with this is worth more right now than ten silent renewals.
Rule packs
This is the part being paid for. CEN, OpenPEPPOL and KoSIT each publish roughly twice a year, and a national CIUS release can change the verdict on invoices that passed last month.
The commitment: a new pack version within 30 days of its upstream release,
with a report of every corpus verdict that changed. Bumps are never silent —
tools/reference-diff.py compares every verdict against KoSIT’s own validator on
each run and the build fails on a disagreement that has not been written down.
Supported frameworks
Every .NET version Microsoft still supports, plus the current LTS. Today that is net8.0 and net10.0, both tested on every commit. A framework is dropped only after Microsoft ends support for it, announced one minor version in advance.
Buying
Email licensing@klarfakt.dev with the organisation name and the tier. Back comes an invoice and a licence certificate naming the organisation. No sales call, no procurement portal, no per-seat audit.
Unsure whether the threshold applies, or whether a particular use counts as production? Ask. A straight answer costs one email.
If the project stops
Every version of Klarfakt becomes Apache 2.0 four years after it is published. The licence sets that as a ceiling and it cannot be extended or revoked — version 1.x converts on 2030-09-04, and later versions carry their own dates.
So the worst case for a customer is ending up with permanently free open-source software, on a schedule that is written down rather than promised.