Tax Revolution Coming February 1st. Big Problems Coming

• The Sejm adopted an amendment to the act introducing mandatory KSeF – large companies will have to use the system from February 2026, and smaller ones from April.
• However, the regulations raise doubts, especially regarding the moment of issuing an invoice.
• Experts warn that in practice this may lead to tax problems and the need for further changes to the regulations.

On Tuesday, the Sejm adopted some of the Senate's legislative amendments to the Goods and Services Tax Act, which aims to introduce the National E-Invoice System (KSeF). The bill will now go to the president's desk.

• From 1 February 2026, companies with sales exceeding PLN 200 million in 2024 will have to issue invoices via KSeF.
• This obligation will apply to smaller companies from 1 April 2026.
• A transitional period has been provided for micro-entrepreneurs – from April to December 2026, they will not have to issue e-invoices if their monthly sales do not exceed PLN 10,000 gross.

The system is intended to standardize document flow and reduce business operating costs. With the implementation of the KSeF, the standard VAT refund deadline will be shortened from 60 to 40 days.

There will be big problems. Tax revolution starting February 1st

Ewa Sokołowska, a tax advisor, told prawo.pl that despite the comments made by tax advisors, the regulations regarding the National Taxpayer Securities Act (KSeF) still raise doubts.

"It may be surprising that relatively little is said about the issue of defining the moment of invoice issuance . This may be due to the fact that many entrepreneurs postpone implementing the KSeF until the last minute. However, in practice, once companies start applying these regulations, they may encounter a number of problems with their interpretation. It is possible that an amendment may be necessary even before the law comes into force," she emphasized.

The portal explained that in accordance with Article 106(1) of the VAT Act, the date of issue of an invoice is the date it is sent to the KSeF.

For example, if a business prepares a structured invoice on March 8th and enters March 8th in field P1 (this field is used to specify the invoice issue date), and then sends it to KSeF on March 11th, the issue date will be March 11th. There are three exceptions to this rule. These apply to invoices issued offline 24/7, issued during a failure, or during KSeF unavailability, where the invoice issue date is always the date in field P1.

The amendment to the VAT Act, as Prawo.pl points out, introduces a new Article 106nda, Section 16, which raises interpretation issues. According to the Ministry of Finance's interpretation, if a taxpayer submits an invoice to the National Tax Administration (KSeF) after the date indicated in field P1, the earlier date, indicated in field P1, will still be considered the date of issue. This structure can pose practical and tax challenges.

- To avoid doubt, taxpayers should, as a rule, send invoices to the KSeF on the same day they prepare them - emphasizes Ewa Sokołowska.