KSeF

With ComCenter, you can send e-invoices to KSeF.

KSeF (Krajowy System e-Faktur) is Poland’s National e-Invoicing System operated by the Ministry of Finance. It is used to exchange structured electronic invoices in the required KSeF format (FA(3)).

Requirements

Permission & License

To use KSeF with ComCenter, users need to have following groups: ComCenter Channel KSeF and ComCenter Management. The tenant needs to have ComCenter Enablement and ComCenter Channel KSeF licenses.

General Information

The KSeF channel supports following authentication methods to connect to the Polish National e-Invoicing System:

Authentication Methods

1. Electronic Signature (Certificate)

• Upload your certificate file (.crt) and private key file (.key) in PEM format.
• Enter the private key password you set when generating the certificate in the KSeF Taxpayer Portal. The KSeF portal always protects the private key with a password — it is required.
• The application verifies the certificate pair and automatically generates a KSeF token for future connections.
• Your private key is used to sign an “Authorization Challenge” but is never permanently stored in the system.

2. KSeF Token

• Use an authorization token generated in the KSeF Taxpayer Portal (Portal Podatnika).
• Tokens provide direct access without requiring certificate management.

Authentication Process

1. Choose your preferred authentication method when creating or updating a KSeF channel.
2. For Certificate: Upload your .crt certificate file and .key private key file, then enter the private key password you set during certificate generation. For Token: Enter your authorization token from the KSeF Taxpayer Portal.
3. The application verifies your credentials with the Polish Ministry of Finance.
4. Upon successful validation, your KSeF channel is activated and ready for use.

Important Security & Validation Requirements

• Ensure the NIP (Tax Identification Number) configured for your channel matches the NIP associated with your certificate or token registration.
• The certificate owner or token user must have the required permissions in the KSeF Taxpayer Portal:
  • “Fakturowanie” (Invoicing) or “Administracja” (Administration)
• Without proper government-side assignments, the Ministry of Finance will reject the connection.
• A Refresh Token is generated after successful authentication, allowing secure background communication.

Troubleshooting Common Issues

1. NIP Mismatch: Ensure the NIP entered in the application matches the NIP configured in the KSeF system or on your certificate/token.
2. Invalid Permissions: Verify in the KSeF Taxpayer Portal that your user account has active “Fakturowanie” or “Administracja” permissions.
3. Token Invalid: Ensure your KSeF token is still valid. If it has expired, generate a new token in the KSeF Taxpayer Portal.
4. Certificate Issues: If using a certificate, verify it has not expired and that both your .crt certificate file and .key private key file are the correct matching pair.
5. Wrong Private Key Password: The password must match exactly what you entered when generating the certificate in the KSeF Taxpayer Portal. The password cannot be recovered — if lost, the certificate must be invalidated via the KSeF portal and a new one generated.

Channel Setup

This chapter describes the basic usage from the end user’s perspective.

Create KSeF channel identity

Users can create and manage their KSeF channel via Channel Management section in the ComCenter.
Each channel is stored encrypted and is only visible to the tenant.

Create channel

1. In the Channel Management Overview, click Add Channel.

1. Select Type KSeF.
2. Add Name for the channel - it must consist only of letters and numbers and between 3 and 250 characters.
3. Add the NIP that is associated to your KSeF system - it must be a standard Polish NIP (Tax Identifier). Once you save the channel, NIP becomes immutable and cannot be edited anymore.
4. Select the Authentication Method:
   • Electronic Signature (Certificate): Upload your .crt certificate file and .key private key file, and enter the private key password you set when generating the certificate. After the first authentication, the certificate is automatically converted to a KSeF token for future use.
   • KSeF Token: Enter the authorization token generated in the KSeF Taxpayer Portal (Portal Podatnika).
5. Click Save.

Update an existing KSeF channel

Opening an existing channel users can update the Name of the channel and the Credentials related to the corresponding NIP. To update the NIP users need to create a new channel.

Channel status

The status of a channel indicates whether the setup and authentication was successful.
It helps users quickly see if the channel can be used for sending and receiving messages. The current status is shown in the Channel Management Overview.

Visibility of KSeF Channels

Each KSeF channel is stored as shared which means all the users that have access to the tenant, will be able to see and modify it.

KSeF channel messaging operations

Currently, all KSeF channel messaging operations are done via API calls.