KSeF is mandatory from 1 February 2026 for large companies and from 1 April for others. From 1 February all buyers must receive cost invoices through KSeF. For the CFO the critical issue is not invoice issuance itself — that is an IT and accounting task. The critical issue is redesigning: the cost invoice approval workflow, the process of coding and allocating costs, internal controls previously relying on PDF invoices, and management reporting that will be fed by data from the KSeF API.
Timeline — who and when
| Date | Who is affected | What is mandatory |
|---|---|---|
| 1 February 2026 | VAT taxpayers with gross turnover >PLN 200m in 2024 | Issuing and receiving invoices in KSeF |
| 1 February 2026 | All buyers (even below the threshold) | Receiving invoices from KSeF-obligated suppliers |
| 1 April 2026 | All other VAT taxpayers | Issuing and receiving invoices in KSeF |
| Until 31 December 2026 | Taxpayers with monthly sales ≤PLN 10,000 | Deferral of issuance obligation (but receiving already mandatory) |
| 1 January 2027 | All remaining taxpayers | Full KSeF obligation; elimination of NIP receipts as invoices |
Opportunities and risks for the finance department
| Opportunity | Risk |
|---|---|
| Automation of cost invoice retrieval — end of manual data entry | No integration of accounting system with KSeF API → manual work instead of automation |
| Faster VAT refund (legally shortened for KSeF users) | Leaky invoice approval process → payments without cost coding or with wrong cost centre |
| Better real-time visibility of payables | Invoices available in the MF system immediately → tax authority sees them before you book them |
| Elimination of duplicate and lost invoices | KSeF outage = no ability to issue invoices → contingency plan required |
What is KSeF 2.0 — brief for the CFO
KSeF (National e-Invoice System) is the Ministry of Finance platform through which, from 1 April 2026, every VAT invoice issued in Poland (with exceptions) must pass. The invoice is submitted in XML format, the MF assigns it a unique KSeF number, and it is available to both transaction parties via the system's API.
A PDF invoice ceases to be a source document. The XML file with the KSeF number becomes the source document. This is a fundamental change for every invoice approval and archiving system.
5 areas the CFO must redesign
1. Cost invoice approval workflow
The existing workflow relied on a PDF forwarded by email or uploaded to a workflow system. In KSeF the invoice is available in the API from the moment the KSeF number is assigned — before anyone sends it by email. The approval workflow must integrate with the KSeF API or with the accounting system fed from KSeF. Processes based on email-forwarded PDF invoices become obsolete.
2. Internal controls over payables
The classic "3-way matching" control (purchase order + goods receipt + invoice) must work on KSeF data. If your ERP retrieves invoices from email or manually — this is an immediate redesign priority.
3. KSeF access rights management
KSeF requires a formal access rights system: who may issue invoices, who may retrieve them, who may view them. This must be documented and auditable. For the CFO — this is a new internal controls area.
4. Contingency plan
What happens when KSeF is unavailable? The law provides for an offline mode with an obligation to submit the invoice to the system once the outage ends. Every company must have a documented contingency plan.
5. Management reporting fed by KSeF data
KSeF data potentially provides better real-time payables visibility. The CFO should plan how to feed the cost dashboard with KSeF API data instead of waiting for the month-end close.
- Identify whether your company is in the first (1 February) or second phase (1 April)
- Check whether your accounting system is integrated with the KSeF API — ready for 1 February (invoice receipt)
- Document the KSeF access rights matrix (issuance / receipt / view)
- Redesign the cost invoice approval workflow — remove email-PDF-based processes
- Prepare and test a contingency plan for KSeF unavailability
- Verify that internal controls cover invoices received via KSeF
- Plan training for the AP team and invoice approvers
Frequently asked questions
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