Digitization of Accounting 2026: How to Prepare Clients for JPK CIT and PIT

The digitization of the Polish tax system is entering a crucial phase. The year 2026 will bring a real revolution for accounting offices and financial departments: new JPK CIT and JPK PIT structures, mandatory digital records, an expanded KSeF, and further electronization of accounting documentation. This is no longer a single change in regulations – it is a complete redesign of the way books are kept and reported to the tax authorities.

1. What exactly will change from 2026?

New JPK structures for PIT taxpayers

From January 1, 2026, individuals conducting business – including those on general principles, flat tax, lump sum, and maintaining KPiR – will be required to submit new JPK structures, covering data from PIT records. This means digital reporting of tax records in a unified format agreed with the Ministry of Finance.

Full digitization of KPiR

Simultaneously from 2026, the tax revenue and expense ledger will have to be maintained exclusively using a computer program – the possibility of keeping it in paper form or in a spreadsheet will disappear. This is another step towards using JPK_PKPiR structures and full automation of data exchange between entrepreneurs and the tax administration.

Digitization of documentation in CIT

In CIT, the digitization process accelerates by expanding the scope of data sent within JPK_KR_PD (JPK from accounting books for income tax purposes). Large entities (with revenues over 50 million euros and tax capital groups) must first adapt their financial-accounting systems so that:

• from January 1, 2025, records include additional markers identifying accounts,
• from January 1, 2026, report, among others, contractor numbers, invoice identifiers in KSeF, and data on differences between the balance sheet and tax result.

In subsequent years, the obligation will be extended to other CIT taxpayers, according to the MF schedule.

KSeF as a "connector" between JPK CIT/PIT and invoices

From 2026, the National e-Invoice System will become the central source of data on structured invoices. Data from KSeF will be linked to accounting records reported in JPK CIT and JPK PIT – including through the invoice identification number in KSeF transmitted in JPK structures.

2. Main challenges for accounting offices

Transition from paper documents to data

So far, accountants have primarily worked with documents – invoices, printouts, PDF files. The digitization of accounting means transitioning to working with data in a structured JPK format: each accounting entry, contractor, document, or balance-tax difference will gain its precise description in the logical structure.

New informational obligations

Expanded reporting requirements in CIT and PIT include, among others:

• detailed identification of accounting accounts,
• linking accounting entries with invoice numbers in KSeF,
• reporting discrepancies between the accounting and tax result,
• regular, periodic submission of complete JPK structures.

Responsibility for data consistency

The tax administration will gain access to more data in near-real-time, increasing analytical capabilities and detecting irregularities. For accounting offices, this means the need to ensure:

• consistency of records in books with data in KSeF,
• unambiguous identification of contractors,
• correctness of account and tax position markings.

3. How to prepare clients for JPK CIT and PIT step by step?

Step 1: Diagnosis of the current state

Start with an organized analysis of each client's situation. In practice, it is worth conducting an audit covering:

• the current way of keeping records (program, Excel, partly paper),
• the degree of use of KSeF or other e-invoicing tools,
• the quality of contractor data (NIP, address data, identifiers),
• document circulation processes (who, when, how delivers documents to the office).

Step 2: Selection and standardization of software

From 2026, it will be crucial to have a system unequivocally compliant with JPK requirements. When choosing and configuring, it is worth paying attention to whether the system:

• supports generating new JPK structures (including JPK PIT records and JPK from accounting books),
• integrates with KSeF and can read invoice identification numbers,
• allows marking accounting accounts according to MF requirements,
• enables automatic data validation before sending JPK.

Step 3: Organizing and standardizing data

The new JPK CIT and JPK PIT require high-quality data. The accounting office should implement organizing actions for clients, such as:

• standardizing contractor files (NIP, national and foreign numbers, names),
• verifying the correctness of income and cost classification,
• reviewing accounting accounts for consistency and assigning markers required in JPK structures,
• establishing rules for describing documents (e.g., type of transaction, source of financing).

Step 4: Rebuilding document circulation processes

In the world of JPK and KSeF, it will be crucial to limit manual document entry. To achieve this, it is worth:

• encouraging clients to switch to invoicing in KSeF as early as possible,
• implementing electronic document workflows within the company (workflow for cost approval, delegations, expenses),
• establishing standards for timely data delivery to the office (e.g., closing the month by the 5th working day),
• automating the import of bank, warehouse, and sales data into the accounting system.

Step 5: Educating clients

The digitization of accounting requires a change in mindset on the part of entrepreneurs. The accounting office can prepare clients by offering:

• webinars and training on JPK CIT, JPK PIT, KSeF, and new obligations in 2026,
• simple instructions (checklists) showing what and in what form the client should deliver,
• communication based on examples – how incorrect data in JPK can result in additional explanations or control.

4. How to use digitization as a competitive advantage?

From accountant to business partner

New obligations can be presented to clients not as "another bureaucracy," but as an opportunity for better control over the company's finances. Thanks to structured data from JPK, the accounting office can offer, among others:

• more detailed profitability analyses of individual business areas,
• ongoing monitoring of differences between the accounting and tax result,
• faster detection of errors and irregularities in documents,
• automatic management reports prepared based on the same data sent to the tax authorities.

Security and reduced risk of control

The digitization of accounting documentation and broader use of JPK are intended to tighten the tax system. For well-prepared clients, this means potentially less burdensome controls and faster clarification of doubts at the data level, without the need to provide stacks of paper documents.

5. What to remember when planning preparations for 2026?

1. Act in advance – system configuration, JPK structure tests, and data migration are processes that take months, not weeks.
2. Think process-wise – it's not just about generating a JPK file, but the entire chain: from issuing an invoice (KSeF), through accounting, to CIT/PIT reporting.
3. Standardize – the more standardized the account names, cost categories, and contractor data, the easier it is to manage reporting quality.
4. Involve clients in the process – they are responsible for the source of many data; without their involvement, even the best accounting system will not ensure full JPK accuracy.
5. Monitor legislation – the scope and timing of the introduction of subsequent obligations (especially in CIT) are spread over several years, so it is worth following MF communications and subsequent regulations.

The digitization of accounting in 2026 – including JPK CIT and JPK PIT – is a major challenge, but also an opportunity to build a new model of cooperation with clients. Accounting offices that start organizing data, streamlining processes, and educating entrepreneurs now will enter the new reporting regime with an advantage that will be difficult for competitors to catch up with.