Quickest way to generate KSeF-compliant XML for Polish SMEs
If you run a business in Poland, this is no longer optional.
From April 2026, invoices must go through KSeF.
Without a valid FA(3) XML file, your invoice simply doesn’t exist in the system.
🇵🇱 What is KSeF (in simple terms)?
KSeF (Krajowy System e-Faktur) is Poland’s official platform for structured e-invoices.
- All invoices must be submitted to KSeF
- Invoices must be in FA(3) XML format
- The system validates and assigns an official ID
- Only then is the invoice considered issued
🚨 What changes in April 2026?
- ❌ PDF invoices alone are no longer valid
- ❌ Sending invoices by email is not compliant
- ✅ Every invoice must be registered in KSeF
- ✅ Structured XML becomes mandatory
Even if you send a PDF, it must be backed by a valid KSeF XML file.
🧾 What is FA(3) XML?
FA(3) is the official structured invoice schema required by KSeF.
- Contains all invoice data in structured format
- Includes buyer/seller identification (NIP)
- Defines totals, VAT, and line items
- Must pass strict validation rules
⚙️ The simplest workflow (no software needed)
1. Enter invoice data
Provide seller and buyer details (including NIP), items, and totals.
2. Generate FA(3) XML
Use a generator that outputs valid KSeF-compliant XML.
3. Upload manually to KSeF
Log into the KSeF portal and upload the XML file.
📤 How manual upload to KSeF works
- Login using your business credentials
- Upload the generated XML file
- KSeF validates the structure
- You receive an official invoice number
🧩 Common problem for SMEs
“I have a NIP, but no system to generate XML.”
This is the exact gap most Polish businesses face right now. You don’t need a complex ERP — you just need a way to create valid XML.
✅ Quick checklist before switching to KSeF
- ☐ Can you generate FA(3) XML?
- ☐ Does it include valid NIP data?
- ☐ Does the file pass validation?
- ☐ Can you upload it to KSeF manually?
🚀 Generate KSeF-ready XML in minutes
Create FA(3) XML + PDF instantly. No signup. Built for Polish SMEs.
Generate KSeF XML