Attention entrepreneurs! Fake invoices at KSeF can wipe out your account

The launch of the National e-Invoice System (KSeF) was intended to improve settlements and exchange of sales documents between contractors. However, the new electronic platform has also become a field for abuse. Just a few days after the system was launched, the first fraud attempts appeared, and small companies are particularly vulnerable.

Fake e-mails impersonating the tax office

Many entrepreneurs received e-mails allegedly sent by the tax office. The sender asked about the level of preparation to use KSeF and asked for an answer. The content included information about the attached “Notification from the Head of the Tax Office” and proposed training and information support.

The Ministry of Finance warned that this was fake news. Fraudsters impersonate tax offices and send e-mails with attachments, trying to extort personal data, bank account numbers, as well as e-mail logins and passwords.

The ministry pays attention to details in the sender’s addresses. For example, criminals used the address (email protected)while the correct address differs by one letter. Similar actions concern fake websites whose addresses only slightly differ from the official websites of the National Tax Administration.

The Ministry of Finance urges that in case of doubt, contact the KAS hotline or the nearest tax office and never provide confidential information in response to suspicious e-mails, text messages or telephone calls. Incidents can also be reported via the CERT platform.

Fictitious and scam invoices in KSeF

The second serious threat is fake invoices. Entrepreneurs may receive documents relating to transactions in which they have never participated. With a large number of similar documents, a moment of inattention is enough to pay for goods or services that the company did not order.

As Joanna Łuksza from iFirma.pl points out, a warning signal may be an invoice from an entity with which the buyer has never cooperated, the inability to contact the issuer, language errors or a very short, unagreed payment deadline.

The KSeF system is to include a function for reporting abuses to the National Tax Administration. However, this tool will be of a technical nature and will not be used to resolve commercial disputes. Solutions are also planned to enable hiding suspicious invoices.

An avalanche of fictitious invoices

The scale of the problem is large. In 2025, over 376,000 were detected in Poland. fictitious invoices, which means an increase of 30%. compared to 2024. As emphasized, the number of detected irregularities was increasing despite the smaller number of customs and tax inspections.

The launch of KSeF was intended to improve the circulation of documents, but at the same time it increased the activity of criminals. Entrepreneurs should carefully verify received messages and invoices so as not to expose the company to the loss of data and money.