Starting February 2026, all VAT-registered companies in Poland will be required to issue and receive invoices through the government’s National e-Invoicing System (Krajowy System e-Faktur, or KSeF).
This is one of the most significant digital reforms in Poland’s tax and accounting landscape since the introduction of JPK (Jednolity Plik Kontrolny) in 2016.
KSeF marks a decisive move toward transparency, automation, and real-time fiscal control — but it also means that businesses must adjust their systems, workflows, and integrations before the deadline.
If your company operates in Poland, or even partly sells or buys within the Polish market, this change will affect you.
📜 The Essence of the Reform
At its core, KSeF is a centralized digital platform operated by Poland’s Ministry of Finance, designed to receive, validate, and store every business-to-business (B2B) invoice issued by VAT-registered entities.
Instead of sending an invoice directly to your customer, your accounting or ERP system will now send it to KSeF, which:
- Validates the invoice structure against the official FA(3) XML schema,
- Assigns a unique KSeF number,
- Confirms the invoice delivery through a digital acknowledgment known as UPO (Urzędowe Poświadczenie Odbioru), and
- Stores the invoice in a secure state-managed archive for 10 years.
Once an invoice is accepted by KSeF, it is legally considered delivered to the customer — even if the recipient never opens the email copy.
In short:
Sending your invoice to KSeF = sending it to your client.
🕰 Why This Change — and Why Now?
Poland has spent nearly a decade tightening its tax compliance mechanisms.
Since 2016, tools like JPK files, the split payment system, and online fiscal cash registers have drastically reduced the VAT gap.
According to the Ministry of Finance:
- In 2015, Poland’s VAT gap was estimated at 24.1%,
- By 2022, it dropped to 4.9%,
- Resulting in PLN 45 billion more annual budget revenue — a remarkable 80% improvement.
(Source: Prezentacja Krajowy System e-Faktur, Ministry of Finance, 2023)
The next step is real-time visibility of invoice data.
With KSeF, the state can immediately verify transaction integrity, reduce fraud risk, and simplify audits.
For businesses, it means less paperwork, faster VAT refunds (40 instead of 60 days), and fewer manual errors in accounting.
🌍 Poland Joins a Global Movement
Poland isn’t alone.
Mandatory e-invoicing is becoming a European standard.
Italy led the way in 2019, followed by countries like France, Romania, and Germany, each adopting its own model or pilot phase.
Here’s how Poland fits into the broader trend:
| Country | System Name | Since | Scope |
|---|---|---|---|
| 🇮🇹 Italy | SDI (Sistema di Interscambio) | 2019 | Mandatory for all domestic B2B invoices |
| 🇫🇷 France | Chorus Pro / PPF | 2024–2026 rollout | Gradual enforcement by company size |
| 🇷🇴 Romania | RO e-Factura | 2024 | B2B and B2G invoices |
| 🇩🇪 Germany | B2B E-Rechnung | 2025 | Federated regional approach |
| 🇵🇱 Poland | KSeF | 2026 | Mandatory nationwide for all VAT payers |
| 🇪🇺 EU Framework | ViDA (VAT in the Digital Age) | 2030–2035 | Planned pan-EU e-invoicing standard |
Poland is therefore not an exception — it’s one of the frontrunners in Europe’s digital transformation of taxation.
Pre-Order Free Now!
Be among the first to access our Odoo ↔ KSeF Connector — the upcoming integration for sending and receiving invoices via Poland’s National e-Invoicing System.
Sign up now for free pre-order to secure early access and updates before release.
🧩 How It Works in Practice
The Core Model
When you issue an invoice in your ERP (like Odoo, SAP, or Comarch):
- Your system generates an XML file compliant with the FA(3) logical structure.
→ See: Information Sheet on the FA(3) Logical Structure, Ministry of Finance, 2024 - It sends the file to KSeF API (official specification – openapi.json)
- KSeF checks the file for errors and assigns a unique KSeF number.
- You receive a UPO – proof that the invoice has been received and is valid.
- The invoice is stored in the KSeF database for 10 years.
- Your client (if VAT-registered in Poland) can access and download the invoice directly from KSeF.
The moment KSeF issues the UPO, the invoice becomes legally binding.
🗓 Implementation Timeline
| Date | Who It Applies To | Status |
|---|---|---|
| February 1, 2026 | Large enterprises (annual turnover > PLN 200 million) | Mandatory |
| April 1, 2026 | All other VAT-registered entities | Mandatory |
| January 1, 2027 | Digitally excluded taxpayers (micro-businesses, invoices < PLN 450) | Grace period ends |
Until the end of 2026, Poland will maintain a transition period — no penalties for minor KSeF-related mistakes, while both e-invoices and traditional PDFs remain acceptable.
💼 How It Affects Different Types of Businesses
1. Companies Operating Only in the Polish Market
| Type | VAT Status | Obligation | System Setup | Example Workflow |
|---|---|---|---|---|
| Domestic company | With VAT | ✅ Mandatory from 2026 | Integrate ERP (e.g., Odoo) with KSeF API | Issue XML → Send to KSeF → Receive UPO → Archive |
| Domestic company | Without VAT | ⚠️ From 2027 (for B2B invoices) | Manual upload via free taxpayer app | Issue invoice → Upload in KSeF → Download UPO |
2. Companies Operating Beyond the Polish Market
| Type | VAT Status | KSeF Scope | Notes |
|---|---|---|---|
| Polish company with foreign sales | With Polish VAT | ✅ KSeF required for all B2B invoices issued to Polish VAT payers | Export invoices (EU, non-EU) may stay outside KSeF |
| Foreign company with Polish branch | With Polish VAT number (NIP) | ✅ Required | Must use its Polish NIP credentials in KSeF |
| Foreign company without Polish VAT | ❌ Not required | — | Invoices can be in any format; KSeF doesn’t apply |
| International group with Polish subsidiary | With Polish VAT | ✅ For intra-Poland operations | Each entity must have its own KSeF token |
| Online sellers (EU/UK) using OSS | ⚠️ Conditional | Only if invoice between Polish VAT entities | Otherwise, out of scope |
🔧 Technical and Integration Details
According to the official OpenAPI documentation (KSeF OpenAPI), integration follows a defined flow:
Step-by-Step KSeF Integration Process
| Step | Description | Technical Reference |
|---|---|---|
| 1️⃣ | Authentication – The ERP connects to KSeF using either a qualified certificate, a trusted profile (ePUAP), or a token. | /api/online/Session/InitToken |
| 2️⃣ | Send Invoice – The system transmits a signed XML file conforming to FA(3)schema. | /api/online/Invoice/Send |
| 3️⃣ | Validation – KSeF validates syntax, issuer identity, and VAT numbers of both parties. | FA(3) Specification, sec. 3.2 |
| 4️⃣ | Receive Response – KSeF returns a JSON response containing: • referenceNumber (unique ID) • timestamp • UPO hash | /api/online/Invoice/GetStatus |
| 5️⃣ | Retrieve or Download Invoice – Both sender and receiver can access it directly in KSeF. | /api/online/Invoice/Download |
| 6️⃣ | Archiving – KSeF retains the document for 10 years; ERP stores reference and link only. | FA(3) Logical Structure, §5.1 |
💡 Note: In the event of a local system outage, companies can switch to “offline mode” — invoices are queued and transmitted once the connection to KSeF is restored.
🧠 What Changes in Daily Operations
Previously, invoices were created in PDFs or printed and sent via email.
Accounting departments had to:
- Verify delivery manually,
- Store invoices physically or on servers,
- Re-send duplicates,
- Handle mismatched data during audits.
With KSeF, those tasks disappear.
Invoices are validated instantly and centrally stored.
Both buyer and seller can access them through the same government system.
Advantages for Businesses:
- Guaranteed delivery and authenticity
- Standardized format (no more mismatched layouts)
- Faster VAT refunds
- Automated posting and reconciliation
- No risk of lost or duplicate invoices
🧮 Accounting and Tax Implications
Before KSeF:
- Invoices were private documents.
- The state saw them only during audits or JPK requests.
- VAT settlements depended on trust and later verification.
After KSeF:
- Every invoice becomes visible to the Ministry of Finance in real time.
- Fraudulent or missing invoices are detected automatically.
- Accountants can automate matching between sales, purchases, and VAT declarations.
Moreover, the Ministry has announced:
- The abolition of corrective notes (replaced by structured corrections in KSeF)
- Integration with JPK_VAT for unified reporting
- No more duplicate invoices — once uploaded, it cannot be “lost”
💻 Integration in Odoo ERP
The ERPixel KSeF Connector
To help companies adapt early, ERPixel, an official Odoo Partner, is developing a free KSeF integration module for Odoo Enterprise and Community editions.
The module connects Odoo’s Accounting and Invoicing apps directly with the KSeF API, automating the entire flow:
| Stage | Action in Odoo | What Happens Behind the Scenes |
|---|---|---|
| 1️⃣ Issue Invoice | Accountant confirms an invoice | Odoo generates FA(3) XML and signs it |
| 2️⃣ Send to KSeF | Button “Send to KSeF” | API call /Invoice/Send, returns KSeF ID |
| 3️⃣ Validation | Automatic | KSeF validates structure and VAT |
| 4️⃣ Receive UPO | Odoo stores KSeF number and UPO in invoice form | |
| 5️⃣ Status Tracking | Cron job checks /Invoice/GetStatus hourly | |
| 6️⃣ Customer Access | Customer portal link to KSeF document | |
| 7️⃣ Archiving | Invoices stored securely in KSeF; Odoo keeps metadata |
The ERPixel module is currently in beta testing, and the company invites Polish firms to join the program.
Participation is free — early adopters will gain support in configuring and verifying their KSeF integration.
👉 To join the beta, contact ERPixel at erpixel.com.
🧭 Step-by-Step Compliance Checklist
- Verify your company’s VAT status.
If you are registered under Polish VAT — KSeF will be mandatory. - Review your ERP or accounting system.
Ensure it supports XML FA(3) and API integration. - Obtain your KSeF access credentials.
Register at podatki.gov.pl/ksef. - Choose your connection method:
- Qualified e-signature,
- Trusted profile (ePUAP),
- API token (for automated systems).
- Test your setup.
Use sandbox environments: - Plan integration with your ERP (Odoo, Comarch, etc.)
Review FA(3) Logical Structure PDF. - Train your team.
Accountants, administrators, and developers must know how to verify UPOs and resolve errors. - Go live before February 2026.
⚙️ Frequently Asked Questions (FAQ)
1. Can I still send invoices by email?
Yes, but it’s optional. The legal proof of delivery is sending it to KSeF.
2. What happens if my system is offline?
You can issue invoices in “offline mode”; once the connection is restored, KSeF receives them with original timestamps.
3. Do I need to send invoices for consumers (B2C)?
No. KSeF applies to B2B invoices only.
4. What about international invoices?
Invoices issued to non-Polish VAT entities remain outside KSeF’s scope but must still comply with EU VAT reporting.
5. Will there be penalties for errors?
Not during the transition period (until the end of 2026). From 2027, fines may apply for missing or incorrect submissions.
🌐 The Broader Vision: Toward EU-Wide e-Invoicing
KSeF is Poland’s national solution — but it aligns with the upcoming EU “VAT in the Digital Age” (ViDA) directive, which aims to standardize e-invoicing and e-reporting across the Union between 2030–2035.
When ViDA arrives, Poland’s infrastructure will already be compliant — giving Polish companies a head start in cross-border trade transparency.
💬 A Word of Reassurance
It’s natural for entrepreneurs and accountants to feel cautious about another “digital obligation.”
But KSeF is not just another bureaucratic burden — it’s a modernization milestone.
The process may require technical adjustments, but it simplifies long-term operations:
- No more lost invoices,
- No need for duplicate storage,
- Faster tax settlements,
- Lower audit risks.
And most importantly, you are not alone.
Free tools from the Ministry of Finance, documentation, and Odoo integrations (like ERPixel’s module) make the transition accessible to every business — from freelancers to multinational groups.
“Many countries have already done this successfully.
Poland is simply taking its turn.”
🏁 Final Thoughts
From February 2026, e-invoicing via KSeF will become a part of everyday business life in Poland.
It’s a shift from isolated company systems to a unified, transparent infrastructure that benefits both the state and the private sector.
For entrepreneurs, accountants, and IT teams, the next 12 months are a perfect time to:
- modernize accounting processes,
- test KSeF integrations,
- and turn this regulatory change into a digital advantage.
The future of invoicing in Poland is structured, automated, and connected — and it starts with KSeF.
References and Official Resources
