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KSeF Setup Guide

KSeF (Krajowy System e-Faktur) is the Polish mandatory national e-invoicing system. It requires all invoices issued in Poland to be transmitted and stored electronically through the government-run platform.

Follow the steps below to obtain the credentials needed to connect Invoicerr to KSeF.

1. Obtain your NIP number​

Your company must have a Polish NIP (Numer Identyfikacji Podatkowej) tax identification number.

  • If you are already registered for tax purposes in Poland, your NIP is your tax ID.
  • If you are a foreign company, you may need to register for a Polish NIP through your local tax office or appoint a Polish fiscal representative.

2. Obtain KSeF access tokens via the Ministry API​

KSeF uses an API-based authentication model. To send invoices you need:

  • NIP — your Polish tax ID
  • Invoice token or authorisation certificate (depending on the integration method)

Get a KSeF token​

Invoicerr's own KSeF channel only ever authenticates with a token — its connection form has no certificate upload at all, so a qualified electronic signature / authorisation certificate (an option KSeF itself offers for other integrations) is not something you can use here.

  1. Log in to the Polish e-Tax portal (podatki.gov.pl).
  2. Navigate to KSeF → Token management.
  3. Generate a new API token for invoice submission.
  4. Set the appropriate permissions (at minimum: invoice:send, invoice:read).
  5. Copy and store the token securely.

3. Configure the KSeF environment​

KSeF has two environments:

EnvironmentURLPurpose
Testhttps://ksef-test.mf.gov.plDevelopment and testing
Productionhttps://ksef.mf.gov.plLive invoice submission

Start with the Test environment, validate your integration, then switch to Production.

4. Connect Invoicerr to KSeF​

Once you have your credentials, configure the KSeF channel in Invoicerr:

  1. Go to Settings → E-invoicing → Channels.
  2. Click Connect on the KSeF card.
  3. Fill in the two fields this channel actually asks for:
    • NIP — your Polish tax ID
    • KSeF token — the API token from step 2 above
    • Environment — TEST or PRODUCTION (the same selector every channel offers)
  4. Save the configuration.

Invoicerr will use these credentials to authenticate with the KSeF API and transmit invoices on your behalf.

Additional resources​