KSeF has permanently changed how invoices flow in Polish businesses. We design integrations that keep this change invisible to your organisation: your shop, invoicing and accounting communicate with KSeF automatically, and your team works just as before.
Since 2026, a B2B invoice formally exists only once it has been submitted to KSeF as an XML file and assigned a KSeF number. The obligation applied to the largest taxpayers from February and to all other businesses from April. For every organisation, this has three consequences:
Every sales invoice must be submitted to KSeF in the format required by the Ministry of Finance. Software without this capability is no longer sufficient.
Supplier invoices are formally received from the system, not from your inbox. Companies that have not automated this process have to manually keep track of two parallel workflows.
The number assigned by the system becomes the invoice identifier and appears, among other places, in payments. Your business systems must store it and pass it on.
The integration is a layer we build between your business software and the API of the National e-Invoicing System. Once live, documents flow as follows:
An order in your online shop, an item in your sales system, a contract in your CRM — the place where your team works every day stays exactly the same.
Our middleware turns sales data into a structured e-invoice (XML in the Ministry’s current schema), validates it and submits it to KSeF via the API — automatically, in the background.
The government system returns an official confirmation and the KSeF number. The integration stores it against the invoice in your system and — on request — sends your customer a readable PDF visualisation.
The integration regularly checks KSeF for new supplier invoices and forwards them to accounting or your approval workflow, so no one has to re-type data from emails and scans.
The regulations provide for an offline mode — the invoice is issued locally and submitted to the system once it is available again. Our integration handles this scenario automatically and keeps track of the submission deadlines.
The invoice for each order reaches KSeF automatically at the moment of sale — whether your shop runs on an off-the-shelf platform or was custom-built by us. In e-commerce, this means automatic invoicing for every order.
We integrate sales and accounting software with KSeF, filling the gaps the vendor did not anticipate: mapping non-standard data, handling corrective invoices and validating before submission.
If your organisation uses custom-built software — your own or one we delivered — we extend it directly with a KSeF module, giving you full control over the process. The custom module connects to KSeF via the API.
Automatic retrieval of invoices from KSeF, assignment to projects or departments and routing for approval — plus an archive where any document can be found in seconds. Receipt, approvals and archive form a single workflow.
Being able to send an invoice is not the same as having a working process. The integration covers the entire workflow: sales in your shop or sales system, issuing, corrections, receiving purchase invoices and archiving — so that no data is ever re-typed between programs.
Formally, a B2B invoice exists in KSeF, but your customers can still receive a readable PDF visualisation — the integration sends it automatically together with the KSeF number. For foreign recipients and consumers, the traditional workflow remains.
The regulations provide for an offline mode: the invoice is created locally with the appropriate marking and submitted to the system once it is available again. A properly designed integration does this automatically and keeps track of the statutory deadlines — one of the things we verify before going live.
We start with a review of your invoicing workflow, then map the data, run the integration in the KSeF test environment and only switch it to production after successful testing. Timing depends on the number of systems — simple implementations are completed within a few weeks.
Yes — we help configure your company’s KSeF authentication, grant permissions to the right people and systems, and store access credentials securely. This is the stage where many businesses run into difficulties right at the start.
Tell us which systems your company uses (shop, sales software, accounting) — we will assess the scope of the integration and how long it will take.