What KSeF is and how to prepare your company
KSeF = Krajowy System e-Faktur (National e-Invoicing System)
Short definition
KSeF is Poland's central, government-run system for exchanging structured invoices. Once mandatory, every B2B invoice is issued and received through KSeF as XML, not as a PDF or paper document.
KSeF, run by Poland's Ministry of Finance, is the platform through which Polish companies issue and receive structured invoices (XML). Instead of emailing a PDF, a company sends the invoice to KSeF, which assigns it a number and makes it available to the counterparty. The goal is to tighten VAT collection and standardise document flow.
For companies using ERP/accounting systems, the key is that their software can talk to KSeF: send invoices, fetch incoming ones and handle KSeF numbers. Comarch ERP Optima, Symfonia and enova365 support KSeF natively. If you sell in another system (shop, CRM, marketplace), you need a flow of invoice -> accounting system -> KSeF.
In practice, if orders are created outside accounting (Allegro, BaseLinker, a B2B portal, a shop), it pays to connect them to the accounting system so the invoice reaches KSeF automatically. We build exactly this kind of integration with Open Mercato as a middleware layer: an order becomes an invoice in Optima/Symfonia/enova365, which then lands in KSeF - with no manual re-entry.
Key facts about KSeF
- KSeF invoices are structured (XML), not PDF.
- Optima, Symfonia and enova365 support KSeF natively.
- Marketplace/shop sales need a flow into the accounting system that submits the invoice to KSeF.
Frequently asked questions
Is KSeF mandatory?
Mandatory e-invoicing via KSeF is being phased in for companies in Poland. Regardless of the exact dates, it pays to prepare your accounting system and integrations early so the transition is painless.
How to connect a shop/Allegro with KSeF?
We connect marketplace/shop orders to the accounting system (Optima, Symfonia, enova365) that handles KSeF. Open Mercato acts as a hub: order -> invoice in accounting -> KSeF, automatically.
Related terms
Want to connect sales to KSeF without re-entering invoices? Let's talk.
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