KSeF Poland Guide

Sandbox Only - KSeF 2.0 Production Environment Not Yet AvailableKSeF 2.0 is currently only available in the sandbox environment. The production environment is expected to launch in February 2026 for large taxpayers. This guide uses sandbox credentials and test data.

Introduction

KSeF (Krajowy System e-Faktur) 2.0 is Poland’s mandatory national e-invoicing system operated by the Ministry of Finance. The system uses the FA(3) XML schema format for structured invoice data and provides real-time clearance for all B2B invoices. Invoices are encoded in FA(3), a strict XML format that enforces standardized fields for domestic and cross-border transactions. The KSeF system validates all submitted invoices in real-time and assigns a unique KSeF ID upon successful clearance. This guide covers two key processes:

Party Registration: Registering suppliers in the KSeF system
Invoice Issuance: Creating and sending FA(3) invoices through KSeF

Prerequisites

To issue invoices through KSeF, you will need:

For Sandbox: Test Polish Tax ID (NIP). You can generate fake NIPs for testing at http://generatory.it/
For Production (when available): Valid company NIP and already logged in to (KSeF MCU Portal)[https://ksef.podatki.gov.pl/modul-certyfikatow-i-uprawnien-mcu/]

Setup

There are three key processes to prepare:

Connect the Poland app
Configure a party registration workflow
Configure an invoice sending workflow

All of the following steps must be carried out from the Invopop Console.

Connect the Poland app

Navigate to Configuration → Apps
Find Poland in the app discovery list
Click Connect to activate

The initial connection requires no configuration.

Configure party registration workflow

Template
Code
Build from scratch

KSeF party registration workflow

Registers a party (supplier) with the KSeF system.

Copy and paste into a new Empty Party workflow code view.

Example Register supplier for KSeF workflow with states

{
    "name": "Register for KSeF",
    "description": "Register a party in KSeF",
    "schema": "org/party",
    "steps": [
        {
            "id": "f6ca2240-fb6b-11f0-b2f4-37a8eb8f9eb9",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `processing`{.state .processing}",
            "config": {
                "state": "processing"
            }
        },
        {
            "id": "e2cd6770-fb6b-11f0-b2f4-37a8eb8f9eb9",
            "name": "Register for KSeF",
            "provider": "gov-pl.register"
        },
        {
            "id": "f0b45d30-fb6b-11f0-b2f4-37a8eb8f9eb9",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `registered`{.state .registered}",
            "config": {
                "state": "registered"
            }
        }
    ],
    "rescue": [
        {
            "id": "ebf99440-fb6b-11f0-b2f4-37a8eb8f9eb9",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `error`{.state .error}",
            "config": {
                "state": "error"
            }
        }
    ]
}

Before starting, review the workflows guide to understand the general setup process.In Console, create a new workflow and choose Empty Party workflow as the base. Then name the workflow with a descriptive label such as “KSeF Register Party”.The new workflow will need to perform these steps:

Set State - To Processing
Register Party in KSeF (Poland) - Registers the party with KSeF
Set State - To Registered

Finally, in the Error Handling area, add the Set State action and select Error.

Configure invoice sending workflow

Template
Code
Build from scratch

KSeF send invoice workflow

Signs and converts the GOBL document into the FA(3) XML format and sends it to KSeF.

Copy and paste into a new Empty Invoice workflow code view.

Example Send KSeF invoice workflow with states

{
    "name": "Send KSeF invoice",
    "description": "Generate FAVAT (3) XML and send it to KSeF",
    "schema": "bill/invoice",
    "steps": [
        {
            "id": "20bbac70-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `processing`{.state .processing}",
            "config": {
                "state": "processing"
            }
        },
        {
            "id": "9b5f5330-fb70-11f0-bcdd-bdb71eaf1fb4",
            "name": "Add Sequential Code",
            "provider": "sequence.enumerate",
            "summary": "Dynamic · KSeF · 000001",
            "config": {
                "name": "KSeF",
                "padding": 6,
                "start": 1
            }
        },
        {
            "id": "2f41c860-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Sign Envelope",
            "provider": "silo.close"
        },
        {
            "id": "2b064190-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Generate FA_VAT v3 XML",
            "provider": "gov-pl.generate"
        },
        {
            "id": "36ec8550-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Send FA_VAT v3 XML to KSeF",
            "provider": "gov-pl.send"
        },
        {
            "id": "3a3e2150-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `sent`{.state .sent}",
            "config": {
                "state": "sent"
            }
        }
    ],
    "rescue": [
        {
            "id": "3eca1210-fb6e-11f0-8a4e-79beeb9e3cf2",
            "name": "Set State",
            "provider": "silo.state",
            "summary": "Set state to `error`{.state .error}",
            "config": {
                "state": "error"
            }
        }
    ]
}

Before starting, review the workflows guide to understand the general setup process.In Console, create a new workflow and choose Empty Invoice workflow as the base. Then add the following steps:

Set State - To Processing
Add sequential code - Add the desired sequence for your invoices
Sign Envelope - Signs the GOBL document preventing further modifications
Generate FA(3) XML - Generates the FA(3) XML
Send FA(3) XML to KSeF - Sends the FA(3) XML to KSeF
Set State - To Sent

In the Error Handling section, add a Set State step with the state set to Error to capture and flag failed submissions.

Running

In this section, we’ll provide details on how to first register a party (supplier) and then issue invoices on their behalf.

The recommended approach is to perform two steps: first upload the document to the silo, then create a job.

Register a Party

Create the Party with Tax ID

For Sandbox: You can use fake Polish Tax IDs (NIP) generated from http://generatory.it/. The sandbox environment doesn’t validate against real company data.

In the Invopop Console, navigate to Parties → Suppliers and click + New Supplier.Create a party entry with the following minimum information:

{
  "$schema": "https://gobl.org/draft-0/party",
  "name": "Test Supplier Sp. z o.o.",
  "tax_id": {
    "country": "PL",
    "code": "9876543210"
  }
}

Click Build, ensure there are no errors, and click Save.

Run the Registration Workflow

Once the party is created, find and click the Select Workflow button on the party details page.Select the KSeF Register Party workflow created during setup and click Run Workflow.

In the sandbox environment, registration completes immediately. No additional steps are required to start issuing invoices.

The party will now be in the Registered state and ready to issue invoices through KSeF.

Send an Invoice

Once a party is registered, you can issue invoices on their behalf. The following examples show partial GOBL documents you can copy and paste directly into the Invopop Console or store via the API as silo entries.

GOBL Invoices sent to KSeF require the following properties:

$regime set to PL
$addons must include pl-favat-v3 for FA(3) schema compliance

B2B Standard Invoice

{
  "$schema": "https://gobl.org/draft-0/bill/invoice",
  "$regime": "PL",
  "$addons": ["pl-favat-v3"],
  "uuid": "01927639-c1a0-7f3a-88d9-5b1f2a5e3c4d",
  "type": "standard",
  "series": "INVOICE",
  "code": "001",
  "issue_date": "2026-01-20",
  "currency": "PLN",
  "supplier": {
    "name": "Testowa Firma Sp. z o.o.",
    "tax_id": {
      "country": "PL",
      "code": "9876543210"
    },
    "addresses": [
      {
        "street": "ul. Główna 1",
        "locality": "Warsaw",
        "code": "00-001",
        "country": "PL"
      }
    ],
    "emails": [
      {
        "addr": "[email protected]"
      }
    ]
  },
  "customer": {
    "name": "Klient Testowy Sp. z o.o.",
    "tax_id": {
      "country": "PL",
      "code": "1111111111"
    },
    "addresses": [
      {
        "street": "ul. Testowa 10",
        "locality": "Kraków",
        "code": "30-001",
        "country": "PL"
      }
    ]
  },
  "lines": [
    {
      "i": 1,
      "quantity": "10",
      "item": {
        "name": "Software Development Services",
        "price": "100.00",
        "unit": "h"
      },
      "taxes": [
        {
          "cat": "VAT",
          "key": "standard",
          "rate": "general"
        }
      ]
    },
    {
      "i": 2,
      "quantity": "5",
      "item": {
        "name": "Consulting Services",
        "price": "150.00",
        "unit": "h"
      },
      "taxes": [
        {
          "cat": "VAT",
          "key": "standard",
          "rate": "reduced"
        }
      ]
    }
  ],
  "payment": {
    "instructions": {
      "key": "credit-transfer",
      "detail": "Transfer payment to our bank account",
      "credit_transfer": [
        {
          "iban": "PL61109010140000071219812874",
          "name": "Testowa Firma Sp. z o.o."
        }
      ]
    }
  }
}

B2B Reverse Charge Invoice

For reverse charge invoices, the process is the same but the customer will have a EU VAT ID:

{
  "$schema": "https://gobl.org/draft-0/bill/invoice",
  "$regime": "PL",
  "$addons": ["pl-favat-v3"],
  "$tags": ["reverse-charge"],
  "uuid": "01927639-c1a0-7f3a-88d9-5b1f2a5e3ccf",
  "type": "standard",
  "series": "RC",
  "code": "001",
  "issue_date": "2026-01-20",
  "currency": "PLN",
  "supplier": {
    "name": "Testowa Firma Sp. z o.o.",
    "tax_id": {
      "country": "PL",
      "code": "9876543210"
    },
    "addresses": [
      {
        "street": "ul. Główna 1",
        "locality": "Warsaw",
        "code": "00-001",
        "country": "PL"
      }
    ]
  },
  "customer": {
    "name": "EU Business GmbH",
    "tax_id": {
      "country": "DE",
      "code": "111111125"
    },
    "addresses": [
      {
        "street": "Hauptstraße 100",
        "locality": "Berlin",
        "code": "10115",
        "country": "DE"
      }
    ]
  },
  "lines": [
    {
      "i": 1,
      "quantity": "1",
      "item": {
        "name": "IT Services - EU Reverse Charge",
        "price": "5000.00"
      },
      "taxes": [
        {
          "cat": "VAT",
          "key": "reverse-charge"
        }
      ]
    }
  ],
  "notes": [
    {
      "key": "legal",
      "text": "Reverse charge mechanism applies - VAT to be accounted for by the customer."
    }
  ]
}

B2B Credit Note

{
  "$schema": "https://gobl.org/draft-0/bill/invoice",
  "$regime": "PL",
  "$addons": ["pl-favat-v3"],
  "uuid": "01927639-c1a0-7f3a-88d9-5b1f2a5e3c8b",
  "type": "credit-note",
  "series": "KOR",
  "code": "001",
  "issue_date": "2026-01-20",
  "currency": "PLN",
  "preceding": [
    {
      "type": "standard",
      "series": "INVOICE",
      "code": "001",
      "issue_date": "2026-01-20",
      "reason": "Price correction",
      "ext": {
        "pl-favat-effective-date": "1"
      },
      "stamps": [
        {
          "prv": "favat-ksef-number",
          "val": "1234567890-20260120-ABCD1234-EF"
        }
      ]
    }
  ],
  "supplier": {
    "name": "Testowa Firma Sp. z o.o.",
    "tax_id": {
      "country": "PL",
      "code": "9876543210"
    },
    "addresses": [
      {
        "street": "ul. Główna 1",
        "locality": "Warsaw",
        "code": "00-001",
        "country": "PL"
      }
    ]
  },
  "customer": {
    "name": "Klient Testowy Sp. z o.o.",
    "tax_id": {
      "country": "PL",
      "code": "9876543210"
    },
    "addresses": [
      {
        "street": "ul. Testowa 10",
        "locality": "Kraków",
        "code": "30-001",
        "country": "PL"
      }
    ]
  },
  "lines": [
    {
      "i": 1,
      "quantity": "10",
      "item": {
        "name": "Software Development Services",
        "price": "10.00",
        "unit": "h"
      },
      "taxes": [
        {
          "cat": "VAT",
          "key": "standard",
          "rate": "general"
        }
      ]
    }
  ]
}

After creating the invoice in the Console:

Click Build to validate
Click Save to store in the silo
Click Select Workflow and choose the KSeF Send Invoice workflow
Click Run Workflow

The invoice will be validated, converted to FA(3) XML format, and sent to KSeF. Upon successful clearance, it will receive a unique KSeF ID.

For international transactions, the invoice is created and cleared in KSeF just like domestic invoices. Because the foreign recipient cannot log into KSeF, delivery happens outside the platform (via email, EDI, etc.) with the KSeF QR code included for verification.

GOBL Addon Reference

Detailed information about the FA(3)-specific extensions and validations can be found in:

You can also use the GOBL Builder to create custom invoices with the Polish regime and FA(3) addon.

🇵🇱 Invopop resources for Poland


Compliance	Invoicing compliance in Poland Compliance timeline
Apps	Poland
Guides	Poland Guide
FAQ	Poland FAQ
GOBL	Poland Tax Regime Polish KSeF FA(3) Addon

Poland FAQ

Find answers to frequently asked questions about invoicing in Poland →

Participate in our community

Ask and answer questions about invoicing in Poland →

KSeF send invoice workflow

Networks

Countries

Set-up

GOBL

Apps

API

Features

KSeF Poland Guide

Introduction

Prerequisites

Setup

KSeF party registration workflow

Running

Register a Party

Send an Invoice

GOBL Addon Reference

Poland FAQ

Participate in our community

Networks

Countries

Set-up

GOBL

Apps

API

Features

​Introduction

​Prerequisites

​Setup

KSeF party registration workflow

KSeF send invoice workflow

​Running

​Register a Party

​Send an Invoice

​GOBL Addon Reference

Poland FAQ

Participate in our community

Introduction

Prerequisites

Setup

Running

Register a Party

Send an Invoice

GOBL Addon Reference