Why should the accounting policy be updated in 2026?

This article answers the following questions:

• From when are KSeF and JPK_CIT mandatory?
• How do the implementation of KSeF and JPK_CIT affect an entity’s internal procedures?

The changes brought about by the obligation to use the National e‑Invoice System (KSeF) in Poland are not limited to organisational adjustments or updates to accounting software. The introduction of structured electronic invoices in our country primarily constitutes a transformation of the manner in which business transactions are documented and therefore necessitates adapting the entity’s accounting policy to this revolution. Why? And what should be kept in mind when approaching this task?

When does KSeF become mandatory? Key timeline of changes 

The obligation to issue e‑invoices in a structured format is being introduced in stages:

• from 1 February 2026 – the implementation of KSeF becomes mandatory for all large enterprises (that is, those whose sales exceeded PLN 200 million in 2025),
• from 1 April 2026 – KSeF must be used by all remaining VAT taxpayers. From this date, the only permissible form of an invoice will be an XML file compliant with the imposed logical structure (which means that it will be necessary to formally describe in the accounting policy the new types of accounting evidence and the methods of processing them).

Why is it necessary to update the entity’s accounting policy?

Pursuant to Article 10 of the Polish Accounting Act, an entity must document the accounting principles it has adopted. The introduction of KSeF changes key aspects of these principles, such as:

• the form of the accounting evidence used,
• the manner in which it is received and verified,
• the procedures for document circulation and archiving. 

This means that updating the accounting policy is no longer a matter of choice – it becomes a statutory requirement.

The changes do not end with KSeF. How does the implementation of so‑called JPK_CIT affect the accounting policy?

Structured electronic invoices are not the only change introduced in 2026 that significantly affects the work of accounting departments.

The tax regulations introducing the obligation to report the so‑called Standard Audit File for CIT (JPK_CIT) require that entities map their existing accounts to the tags set out in the Regulation of the Minister of Finance.

As a result, it may turn out that an entity’s chart of accounts will need to be adjusted in order to enable its linkage to the existing JPK_CIT tags. Changes to the chart of accounts (which constitutes an element of the entity’s accounting policy) therefore imply the need to amend the accounting policy itself.

From when is JPK_CIT mandatory? 

The new reporting obligations requiring entities to submit the Standard Audit File for CIT to the tax office apply:

• from 1 January 2025 – for tax capital groups and large CIT taxpayers (with revenues exceeding EUR 50 million),
• from 1 January 2026 – for other CIT and PIT taxpayers (keeping accounting books) who are obliged to file JPK_V7M,
• from 1 January 2027 – for all remaining CIT and PIT taxpayers (keeping accounting books).

What will the statutory auditor examine? The audit perspective

Entities should remember that during the financial audit, the statutory auditor verifies not only the compliance of the accounting books but also the accounting policy itself with the provisions of the Accounting Act. Therefore, the lack of an accounting policy adapted to the changes introduced in Poland in 2026 may be considered a weakness of internal control.

With this in mind, we remind you that it is not advisable to wait until the financial statements are audited before updating internal procedures – the sooner the entity introduces the necessary amendments to its accounting policy, the better. All entities wishing to update their accounting policy in light of the legislative changes are encouraged to arrange a consultation with statutory auditors who, thanks to their extensive experience, will be able to appropriately adapt the previously used solutions to the dynamic changes taking place in Polish regulations.