Since 2025, significant changes have applied to the obligation to keep accounting books (full accounting) for various forms of business. The new threshold, set at EUR 2.5 million, is a significant increase compared with previous years. This change means that some entrepreneurs who previously had to keep accounting books can stay with simplified tax records. Our accounting firm in Warsaw keeps both the KPiR and ryczałt records and full accounting books.
Raising the threshold from EUR 2 million to EUR 2.5 million is not the only change. Equally important is the change in the basis: since 2025, net revenue from the sale of goods and products is what counts, without financial operations (Act of 6 December 2024, Dz.U. (Journal of Laws) 2024, item 1863). The rules require entrepreneurs to analyse their turnover for 2025 carefully and to prepare for possible changes to their accounting system from 1 January 2026.
In 2026 the threshold for keeping accounting books is the equivalent of EUR 2.5 million in Polish currency, i.e. PLN 10,646,500. This means that entrepreneurs whose net revenue from the sale of goods and products for 2025 was at least this amount must keep full accounting books from the beginning of 2026. The legal basis is Article 2(1)(2) of the Accounting Act (consolidated text: Dz.U. 2026, item 522) and Article 24a(4) of the PIT Act
Entities required to keep accounting books
The Accounting Act and the Personal Income Tax Act set out precisely which businesses may be required to keep accounting books if they exceed the revenue threshold. The list covers a variety of business forms, from the simplest to more complex organisational structures.
Under the current law, the obligation to keep accounting books from 1 January 2026 applies to the following entities if their net revenue from the sale of goods and products for 2025 was at least the equivalent of EUR 2.5 million in Polish currency:
- Natural persons doing business on their own account
- Civil-law partnerships of natural persons (spółka cywilna) as one of the most popular forms of business cooperation
- Civil-law partnerships of natural persons and enterprises in probate in special legal situations
- General partnerships of natural persons (spółka jawna), in which the partners have full liability
- Professional partnerships (spółka partnerska) intended for the liberal professions
- Enterprises in probate operating under the Act on succession management of an enterprise
Civil-law partnerships of natural persons are one of the most common forms of business cooperation in Poland. If the net revenue of such a partnership from the sale of goods and products in 2025 was at least PLN 10,646,500, the partnership must switch to keeping accounting books from January 2026 (from 1 January 2027 the threshold is PLN 10,942,500 – for revenue for 2026). This applies both to partnerships providing services and to those engaged in trade or production
Particular attention should be paid to enterprises in probate operating under the Act of 5 July 2018 on succession management of an enterprise. Despite their specific legal nature, these entities are also required to keep accounting books if they exceed the revenue threshold.
It is worth stressing that these rules do not apply to capital companies, which are required by law to keep accounting books regardless of their revenue. This applies to sp. z o.o. (limited liability company), joint-stock companies (spółka akcyjna) and other capital forms of business.
Converting the threshold into Polish currency in 2026
The way the threshold for keeping accounting books is converted from euro into Polish zloty is strictly regulated by law and requires a specific exchange rate on a specific date. This process is crucial for entrepreneurs, who must determine precisely whether their revenue has exceeded the threshold requiring accounting books.
Under the applicable rules, the threshold is converted into Polish currency at the average exchange rate announced by the National Bank of Poland (NBP) for the first business day of October of the year preceding the financial year (Article 3(3) of the Accounting Act). For 2026, the rate from the first business day of October 2025 was used.
The euro rate used to convert the threshold for 2026 is PLN 4.2586 per euro (NBP table of 1 October 2025). This rate is the basis for calculating the threshold amount in Polish zloty. Entrepreneurs must use only this rate, regardless of current fluctuations of the euro. For 2027 the rate of 1 October 2026 applies – PLN 4.3770 per euro, i.e. PLN 10,942,500
The calculation of the amount requiring accounting books in 2026 is as follows:
- Threshold in euro: EUR 2,500,000
- NBP rate from October 2025: PLN 4.2586 per euro
- Threshold amount: EUR 2,500,000 × PLN 4.2586 per euro = PLN 10,646,500
This means that entrepreneurs whose revenue for 2025 was at least PLN 10,646,500 are required to keep accounting books from 1 January 2026. This amount is the threshold at which the accounting obligation arises.
Comparison of thresholds in previous years
The threshold amount in zloty changes every year together with the euro exchange rate, and in 2025 it rose mainly because the euro threshold was raised. Raising the threshold is intended to relieve smaller entrepreneurs of the obligation to keep complex accounts.
| Financial year | Threshold in euro | NBP rate | Amount in PLN | Percentage change |
|---|---|---|---|---|
| 2024 | 2,000,000 | 4.6091 | 9,218,200 | - |
| 2025 | 2,500,000 | 4.2846 | 10,711,500 | +16.2% |
| 2026 | 2,500,000 | 4.2586 | 10,646,500 | -0.6% |
Raising the threshold from EUR 2 million to EUR 2.5 million in 2025 meant a 25% increase in euro. However, the actual increase in the threshold amount in Polish zloty was 16.2% because of the lower euro rate in October 2024.
The increase of the threshold for keeping accounting books by EUR 500,000 from 2025 means that some entrepreneurs who were previously required to keep accounting books can return to simplified tax records. This mainly concerns companies with a turnover of between PLN 9.2 million and PLN 10.7 million a year
Consequences of exceeding the threshold
Exceeding the threshold for keeping accounting books has a number of significant legal, organisational and financial consequences for entrepreneurs. These changes require proper preparation and adaptation of the whole accounting system to the new requirements.
The basic consequence of reaching the threshold of PLN 10,646,500 in revenue in 2025 is the obligation to keep full accounting books from 1 January 2026. This means giving up simplified tax records and switching to an accounting system compliant with the Accounting Act.
The main consequences of exceeding the threshold include:
- Keeping an accounting journal with a chronological record of all business transactions
- Keeping a general ledger containing all synthetic accounts
- Keeping subsidiary ledgers for detailed records of receivables, liabilities and assets
- Preparing a balance sheet and a profit and loss account at the end of the financial year
- Applying the rules for valuing assets and liabilities in line with the Accounting Act
Entrepreneurs required to keep accounting books must also follow detailed rules for documenting business transactions. Each accounting document must contain certain formal elements and be properly described and approved by authorised persons. Failure to comply with these requirements may result in financial penalties
Additional obligations arising from keeping accounting books are:
- Stocktaking of assets, as a rule as at the last day of each financial year
- Retention of accounting documents for at least 5 years from the beginning of the year following the financial year (Article 74(2)–(3) of the Accounting Act), and of tax documents – until the tax liability becomes time-barred (Article 86 § 1 of the Tax Ordinance Act (Ordynacja podatkowa))
- Protection of the books against destruction or unauthorised access
- The possibility of audits by the tax authorities of whether the books are kept correctly
Preparing to change the accounting system
Moving from simplified tax records to full accounting books requires careful organisational and technical preparation. Entrepreneurs who have exceeded the revenue threshold should start preparing several months before 1 January 2026.
Key stages of preparing to change the accounting system:
- Analysis of the existing records and identification of all assets
- Choice of a suitable accounting system adapted to the nature of the business
- Setting up a company chart of accounts compliant with the Accounting Act
- Stocktaking of assets as at 31 December 2025
- Training staff in the new accounting procedures
- Preparing documentation describing the accounting policies adopted
The choice of accounting system should take into account the specifics of the industry, the size of the business and planned development. Modern accounting systems automate many processes, which makes keeping accounting books much easier and reduces the risk of errors. It is also important to protect accounting data properly
Particular attention should be paid to the opening balance sheet as at 1 January 2026, which must reflect the actual assets and liabilities of the business. This balance sheet is the starting point for keeping the accounting books and must be prepared with the utmost care.
Valuation rules in accounting books
Keeping accounting books requires precise rules for valuing assets and liabilities, which differ significantly from the simplifications used in tax records. These rules are crucial for presenting the financial position of the business fairly.
The basic valuation rules in accounting books include:
- Fixed assets are valued at purchase price or production cost, less depreciation
- Inventories are valued at purchase price or production cost, not higher than the net selling price
- Receivables are shown at nominal value, less impairment write-downs
- Liabilities are shown at nominal value
- Short-term investments are valued at purchase price or fair value
Valuation rules in accounting books have a direct effect on the financial result of the business and on the tax base. Applying these rules correctly requires good knowledge of the Accounting Act and regular monitoring of regulatory changes. Valuation errors can distort the picture of the company's financial position
Correct recognition of provisions and accruals is particularly important, as it allows revenue and costs to be allocated to the right reporting periods. These elements are often the biggest challenge for entrepreneurs moving from tax records to accounting books. How they are recognised is set out by each entity in its accounting policy.
Accounting documents and archiving
Keeping accounting books requires detailed documentation of all business transactions. Accounting documents must meet certain formal requirements and be properly archived for the required period.
Basic requirements for accounting documents:
- Document name and its identification number
- Date of issue and date of the business transaction
- Details of the contractor or party to the transaction
- Description of the business transaction stating its nature
- Transaction amount expressed in Polish zloty
- Signatures of the persons responsible for approving the document
Accounting documents must be stored in a way that keeps them durable and legible for the whole required period. Electronic documents require appropriate technical and organisational safeguards. Loss or destruction of accounting documents can have serious legal and financial consequences
A manufacturing company that exceeded the accounting threshold had to organise a completely new system for documenting business transactions. It introduced document numbering, document flows between departments and an electronic archiving system. Particular attention was paid to documenting warehouse operations and settlements with foreign contractors.
Audit and supervision of accounting books
Accounting books are subject to close scrutiny by the tax authorities and other supervisory bodies. Entrepreneurs must be ready for audits and ensure that their accounting records are fully available.
Bodies authorised to audit accounting books:
- Tax offices (urząd skarbowy) with regard to the correct determination of the tax base
- Customs and tax offices as part of a customs and tax audit
- ZUS (Social Insurance Institution) with regard to contribution settlements
- PIP (National Labour Inspectorate) with regard to compliance with labour law
- The Office of Competition and Consumer Protection in certain cases
A tax audit of an entrepreneur is, as a rule, preceded by a notice of the intention to start it (Article 282b § 1 of the Tax Ordinance Act), and the exceptions in which no notice is sent are listed in Article 282c of the Tax Ordinance Act. The audit bodies have the right to inspect all accounting documents and to make copies and extracts from the books. Entrepreneurs must give explanations and make all required documents available
Preparing for an audit requires:
- Organising all accounting records so that documents can be found quickly
- Preparing explanations of unusual business transactions
- Providing access to the accounting system and the ability to present data
- Designating the persons responsible for contact with the audit bodies
