National e-Invoicing System (KSeF) has ceased to be a mere technological announcement and has become a binding legal reality. This change redefines the way we understand the issuance of sales documents - an invoice is no longer a PDF file sent by email, but a structured set of digital data in XML format. But before your company can send the first document to the Ministry's system, it must go through a key step: successful authentication. This is the process of confirming identity, which is the digital key to the gates of the Ministry of Finance. Without it, the system will not recognize your authorization to operate under a specific number NIP (Tax Identification Number)..
Depending on whether:
Your path to KSeF will be different. We have prepared for you a summary - a kind of „road map” of logging.
The most common questions we encounter are: how to set up KSeF user account?
The good news - the account is not created. It's already there (assigned to NIP), you just need to prove that you have the right to use it.
Individual (non-business) / JDG (sole proprietorship)
Here the matter is the simplest. You are the „rudder, sailor and ship.”.
Method: you authenticate „yourself”.
Tools: free Trusted Profile or Qualified Electronic Signature (QES).
Action: you log in directly. The system recognizes your PESEL associated with the company's NIP.
Commercial Law Companies (Limited Liability, Joint Stock, Limited Partnership, General Partnership) Here we enter the world of „non-individual entities.” The company has no hands to sign, nor does it have PESEL. Instead, it has NIP.
Method - option recommended: Qualified Electronic Seal. This is a digital version of the company stamp. It allows you to automate and make your processes independent of a specific individual (such as the CEO, who may be on vacation).
Traditional option: filing a report ZAW-FA at the Tax Office. In it, you designate a specific person (e.g., the CEO) who will use their personal signature to log in on behalf of the company.
„Third sector” entities” and others (Associations, Foundations, Cooperatives, Housing Communities).
The principle is similar to that of companies. Questions are often asked: is KSeF mandatory for all entrepreneurs? Yes, also for active VAT taxpayers in these groups.
Method: if the entity has NIP, it can produce an electronic seal.
Alternative: If the board is multi-member or you don't want to invest in a seal, you will need to file a ZAW-FA to authorize an individual (such as the property manager or treasurer of the association) to log in.
Local Government Units (JST - Municipalities, Counties) - a river topic: the municipality as a „super-taxpayer” has schools, kindergartens (budget units) under it.
Main Office: shall be authenticated with a qualified seal or indicate the person (Mayor/Mayor) by ZAW-FA.
Subordinate units: they receive powers granted „from above” by the main unit or use powers in a hierarchical model.
Electronic Stamp is the digital equivalent of a company stamp. It is she who allows ERP systems to send invoices in bulk, automatically, without involving employees for each signature. Provides independence from personnel changes and the highest level of data security.
Automation
Finance and accounting systems need a seal to „sign” bulk mailings without a human being and an accountant clicking each time.
Security and Integrity:
The seal guarantees that the document is from a specific company and has not been altered after it was issued.
Independence
Employees may leave the company, but the stamp assigned to the organization's NIP remains, ensuring continuity of processes without the need to submit new ZAW-FA forms with each personnel change.
The Ministry of Finance has provided for emergency scenarios. If the system is unavailable, an invoice can be issued with a QR code (Quick Response - a graphical code that allows quick reading of data), which must be sent to the system within one business day after the failure has ceased.
Remember, however, that a KSeF Type 2 Certificate is required to generate the issuer's identity verification codes in OFFLINE mode.
KSeF is not just a new tax obligation, it's a digital leap for your business. The key to a smooth transition through this revolution is choosing the right digital identity.
Whether you run a small JDG or manage a large joint-stock company, take care of your signature or seal today. Don't wait for the final bell or a system failure on the last day of the deadline.
If you need help getting a qualified electronic seal or signature check out the offer on podpisano.pl.
For more information about KSeF procedures, visit the official website ksef.podatki.gov.pl And in our knowledge base.
The article is based on Handbook KSeF 2.0 (MF, September 2025) and information from ksef.podatki.gov.pl.
