2026 brings entrepreneurs a number of significant changes: mandatory KSeF, new JPK_CIT files, modified health insurance contribution rules and updated tax limits.
2026 is one of the most demanding periods for Polish entrepreneurs in terms of changes in tax law. The National e-Invoice System is becoming mandatory, the scope of JPK reporting is being expanded, and the rules for calculating the health insurance contribution are being modified once again. In this article we discuss the key changes that affect both sole traders and sp. z o.o. companies — so that you know what to prepare and what to pay particular attention to.
The National e-Invoice System (KSeF) is no longer voluntary. From 2026, all active VAT taxpayers are required to issue structured invoices exclusively through the KSeF system. This means the end of traditional PDF invoices sent by email as the primary form of documenting B2B transactions. Entrepreneurs must take care of several matters: • Adapting their accounting or invoicing software to KSeF requirements. • Training employees responsible for issuing invoices. • Verifying whether business partners are ready to receive invoices via KSeF. • Implementing contingency procedures in the event of system unavailability. Invoices issued outside KSeF (without a valid reason) will be treated as not issued, which may result in tax penalties. It is worth updating your company's invoicing processes as soon as possible.
2026 also sees the expansion of reporting obligations under the Jednolity Plik Kontrolny to include the JPK_CIT structure. This obligation applies to CIT taxpayers and involves regularly submitting detailed data from the accounting books to the tax office (US) in a standardised electronic format. In practice, JPK_CIT covers, among other things: • A summary of accounting transactions together with their classification. • Data relating to fixed assets and intangible assets. • Information on settlements with business partners. The introduction of JPK_CIT requires adapting accounting systems to the new XML schema. Sp. z o.o. companies and other entities settling CIT should, in cooperation with their accounting office, verify whether their software generates files compliant with the current specification of the Ministry of Finance. Data discrepancies may result in requests for explanations or audits.
Similar changes in reporting apply to entrepreneurs keeping the tax revenue and expense ledger (KPiR). The JPK_PKPIR structure imposes an obligation to submit ledger data in electronic format, enabling tax authorities to verify settlements on an ongoing basis. For sole traders and partnerships settled on general principles or flat-rate income tax, this means the need to: 1. Ensure that the software used for keeping KPiR is compatible with the JPK_PKPIR requirements. 2. Regularly export and archive data in the required format. 3. Verify the accuracy of entries — errors in JPK may result in corrections and explanations before the tax office (US). If you keep your accounts yourself, be sure to check the updates to your software. If you use an accounting office — make sure it is ready for these changes.
The rules for calculating the health insurance contribution remain one of the most frequently changing elements of the tax system in recent years. In 2026, modified regulations are in force that affect entrepreneurs in different ways depending on their chosen form of taxation. The most important issues: • Entrepreneurs on the tax scale and flat-rate income tax — the health insurance contribution is calculated on income, with updated minimum thresholds linked to the minimum wage. • Lump-sum taxpayers — the amount of the contribution depends on the revenue bracket, which has been updated. • The changes also concern the possibility (or lack thereof) of deducting the health insurance contribution from tax or income — it is worth verifying the current regulations for your form of taxation. Entrepreneurs should verify every year whether their chosen form of taxation is still optimal for them — particularly in the context of contribution burdens.
The 2026 tax changes also include an update to key limits and thresholds that are relevant to many entrepreneurs: • Small VAT taxpayer limit — determines the right to quarterly settlements and the cash accounting method. • Small CIT/PIT taxpayer limit — affects the right to the reduced CIT rate (9%) or lump-sum taxation on revenues. • Thresholds for lump-sum taxation on recorded revenues — determine the possibility of applying this form of taxation. • Estonian CIT limits — updated revenue thresholds for companies wishing to use the lump-sum tax on company income. It is worth remembering that exceeding certain thresholds during the year may result in the loss of preferential settlement conditions. Regularly monitoring revenues and comparing them with current limits is an element of good financial management of a company.
Effective preparation for tax changes requires acting in advance. Here is a practical list of steps: 1. Software audit — check whether your invoicing and accounting systems support KSeF, JPK_CIT and JPK_PKPIR. 2. Team training — people responsible for invoicing and accounting must be familiar with the new procedures. 3. Verification of the form of taxation — new health insurance contribution rules and changes to limits may mean it is worth considering a change of taxation form for 2026. 4. Contact with your accounting office — professional accountants will help assess the impact of the changes on your company and propose optimal solutions. 5. Updating contracts and regulations — some changes may require adjustments to the provisions of contracts with business partners. Do not wait until the last moment — implementing changes with adequate lead time reduces the risk of errors and potential penalties.
The tax changes in 2026 are wide-ranging and affect almost every entrepreneur — regardless of legal form or scale of activity. Mandatory KSeF, expanded JPK, a modified health insurance contribution and new limits require a conscious approach and adequate preparation. If you want to make sure your company is ready for these changes, contact Danexis — call +48 780 760 666, write to kontakt@danexis.pl or visit us at ul. Braniborska 74/20 in Wrocław. We will help you adapt to the new regulations and optimise your settlements.