Tax books: KPiR and the revenue register alongside full accounting

Zaksio supports three ways of keeping records: full accounting (accounting books), the tax revenue and expense ledger (KPiR) and the revenue register for flat-rate taxpayers. The way of keeping books is a property of the company: you choose it in "First steps", in the tax profile.

How they differ

• Full accounting: chart of accounts, general ledger, balance sheet and profit and loss account. Mandatory for limited liability, joint-stock and limited partnerships and for businesses whose net revenue from the sale of goods and products in the previous financial year was at least the equivalent of EUR 2,500,000 (art. 2(1)(2) of the Accounting Act).
• KPiR: the tax ledger in the layout from the regulation of the Minister of Finance and Economy of 6 September 2025 (Dz.U. 2025 item 1299), in force from 1 January 2026, with 19 columns. For taxpayers on the tax scale or flat tax.
• Revenue register: the flat-rate taxpayer's ledger under the regulation of 6 September 2025 (Dz.U. 2025 item 1294), with 17 columns and rates of 17, 15, 14, 12.5, 12, 10, 8.5, 5.5 and 3%.

How to choose the way of keeping books

Zaksio suggests a value from the legal form and the form of taxation, and blocks an incompatible choice with an explanation. Limited liability, joint-stock and limited partnerships keep full accounting only. A sole proprietorship, a civil-law partnership, a general partnership of natural persons and a professional partnership can keep KPiR, a revenue register or full accounting. The tax scale and flat tax mean KPiR, flat-rate tax means the revenue register.

1. On the dashboard, in the "First steps" card, open the company's tax profile.
2. Choose the legal form and the form of taxation.
3. In the "Way of keeping books" field leave the suggestion or choose another permitted way, and save the profile.

Where entries come from

Ledger entries are created automatically from sales and purchase invoices (including those fetched from KSeF), payroll and depreciation. You can also add a manual entry. The ledger screen shows the columns of the layout, monthly totals and the income calculated according to explanation 22 to the layout. With KPiR and the revenue register the menu shows the matching ledger instead of the "General ledger".

A wrong entry: reversal (storno)

The ledger is append-only. You correct a mistake with a reversal entry, that is a new entry with a minus sign (§ 6 of the regulation), not by editing or deleting. The original entry and its correction both stay in the ledger.

Tax-deductible costs

For each purchase item the AI team proposes what part of the expense is a tax-deductible cost, and you approve it. The AI does not calculate amounts. The rules from the PIT Act are written in code:

• Entertainment: 0% (art. 23(1)(23)).
• Passenger car also used privately: 75% (art. 23(1)(46a)).
• An item above PLN 10,000 net: a signal that it may be a fixed asset (art. 22d).

Changing the way during the year and back-filling

When you change the way of keeping books, the general ledger data stays and new entries in the tax ledger are created from the moment of the change. You add earlier documents from this year with the "Complete from documents" button.

PIT from the ledger

PIT advances and returns (tax scale, flat tax PIT-36L, flat-rate tax PIT-28) are calculated from these books, and for flat-rate tax from revenue at the rates from the register. They are drafts for review, with no automatic submission to the tax office.