KSeF Access and Token 2026 - Sole Proprietor Guide

KSeF implementation most often fails not on the invoice itself, but on access. As a sole proprietor, you need to determine who logs into the system, who grants permissions, which tool you use, and whether your integration requires a token or certificate.

Start with role assignment

First determine who does what in your process:

• Owner (you) -- primary access, can grant permissions
• Accounting software -- automated access via token
• Accountant -- if applicable, delegated permissions

Access methods

1. Qualified certificate

• Highest security level
• Required for some operations
• E-dowod or commercial certificate

2. Authorization token

• Generated in the KSeF portal
• Used for software integrations
• Valid for a set period

3. Trusted profile (Profil Zaufany)

• Used for portal access
• Cannot be used for API integrations

Practical steps

1. Log into the KSeF test environment at ksef-test.mf.gov.pl
2. Generate a test token
3. Configure your invoicing software with the test token
4. Issue a test invoice
5. Verify it appears correctly in the system
6. Repeat with production environment when ready