Do You Have to Keep Full Accounting Books from 1 January 2027? The Revenue Limit and What Counts Toward It

For many entrepreneurs who keep a tax revenue and expense ledger (KPiR), “accounting books” sound like something reserved for capital companies and large firms. In fact, the obligation to keep them also applies to individuals running a sole proprietorship and to partners in civil-law partnerships, general partnerships and professional partnerships, if they exceed the statutory revenue limit. “Accounting books” means full accounting, a more extensive form of record-keeping than the KPiR. Revenue from 2026 will determine whether the obligation applies from 1 January 2027.

Who is affected

The Accounting Act imposes the obligation to keep accounting books on:

natural persons,
civil-law partnerships of natural persons,
general partnerships of natural persons,
professional partnerships,
estates of deceased entrepreneurs operating under the Act on the Succession Management of a Natural Person’s Enterprise and Other Facilitations Related to Enterprise Succession (including civil-law partnerships of natural persons and enterprises in inheritance).

The obligation arises when net revenue from the sale of goods and products in the previous financial year was at least the equivalent of EUR 2,500,000 in Polish currency.

How to determine the limit in zloty

The euro limit is converted into zloty at the average NBP exchange rate announced on the first business day of October of the year preceding the financial year.

The rate of 1 October 2026 is PLN 4.3770/EUR (NBP table no. 191/A/NBP/2026).

EUR 2,500,000 × PLN 4.3770/EUR = PLN 10,942,500

This amount is the limit that determines the obligation to keep accounting books from 1 January 2027.

Important: the scope of revenue taken into account differs between the Accounting Act and the PIT Act. So when determining the limit, it is not enough to check just one act.

Accounting Act – what counts toward the limit

Under Article 2(1)(2) of the Accounting Act, net revenue from the sale of goods and products in the previous financial year counts. For the limit applicable in 2027, this means revenue earned in 2026.

After the changes in force since 2025, revenue from financial operations is no longer included in the limit as a separate category. Other operating revenue is also not automatically added up.

PIT Act – the scope is broader

According to Article 24a(4) of the PIT Act, the obligation to keep accounting books applies to natural persons, civil-law partnerships of natural persons, general partnerships of natural persons and professional partnerships whose revenue within the meaning of Article 14 of the PIT Act for the previous tax year reached at least the euro equivalent specified in the accounting regulations.

This means that, for PIT taxpayers, it is not only net revenue from the sale of goods and products that is taken into account.

What this means for an entrepreneur keeping a KPiR

A natural person keeping a KPiR in 2026 who is checking whether they must switch to accounting books from 1 January 2027 should add up their revenue from business activity as determined under the PIT Act. It may be higher than the net revenue from the sale of goods and products referred to in the Accounting Act.

Example

An entrepreneur who is a natural person keeps a KPiR in 2026. This year they earned:

PLN 10,900,000 in net revenue from the sale of goods and products,
PLN 50,000 in interest on funds held in business bank accounts, which constitutes revenue from business activity within the meaning of the PIT Act, but is not net revenue from the sale of goods and products within the meaning of the Accounting Act.

Sales of goods and products alone (PLN 10,900,000) are below the limit of PLN 10,942,500. However, for the obligation to keep accounting books, what counts is revenue from business activity under the PIT Act:

PLN 10,900,000 + PLN 50,000 = PLN 10,950,000

The limit of PLN 10,942,500 has been exceeded, so the entrepreneur will be required to keep accounting books from 1 January 2027.

In the case of a natural person keeping a KPiR, when assessing the obligation to switch to accounting books, all revenue from business activity as defined under the PIT Act must be taken into account, and its scope may be broader than under the Accounting Act. Even a relatively small incidental revenue, such as interest on funds in a business account, can decide whether the limit is exceeded.

Legal basis
– Art. 14 and Art. 24a(4)–(4f) of the Act of 26 July 1991 on Personal Income Tax (consolidated text: Journal of Laws of 2026, item 592),
– Art. 2(1)(2), Art. 3(1)(30a) and Art. 3(3) of the Act of 29 September 1994 on Accounting (consolidated text: Journal of Laws of 2026, item 522).