Preparing an organisation for JPK CIT reporting

The implementation of JPK CIT reporting within a company constitutes one of the most complex tax and technology projects of recent years. It is a process that requires organisations both to introduce appropriate technological solutions – including the proper adaptation of their ERP system or financial and accounting software – and to comprehensively organise the information that will be used for reporting purposes. This primarily includes identifying data sources and methods of generating data, but also substantively verifying the consistency and compliance of information provided to the tax authorities with information reported in connection with other tax obligations. This means that – in order to avoid errors – a genuinely broad perspective must be adopted.

Implementing JPK CIT reporting requires considerable time and effort

Due to the entry into force in 2026 of the obligation to implement the National e-Invoicing System (KSeF), the implementation of which required substantial resource commitment within Polish companies, many entities postponed activities related to JPK CIT reporting implementation until the second half of 2026.

Although the mandatory reporting deadline for most CIT taxpayers is not until 31 July 2027, delaying the necessary activities for too long may prove costly. As tax advisers with extensive experience in coordinating business processes, we therefore recommend taking prompt action to implement JPK CIT reporting within your organisation.

It should be remembered that if accounting systems do not contain the required data (or if changes result in incorrect entries appearing within them), those systems will need to be modified appropriately in order to comply with the new obligations. Consequently, the later implementation work begins, the greater the number of accounting entries that may require adjustment.

Let us therefore discuss the key stages in preparing an organisation for JPK CIT reporting.

Technical preparation of the software used to create JPK CIT files

A key aspect of the JPK CIT reporting implementation process is the preparation of an appropriate technical infrastructure.

In the case of financial and accounting systems supplied by Polish vendors or using dedicated Polish localisation packages, companies can generally expect software updates and the possibility of installing an appropriate interface enabling the generation and submission of JPK CIT files in the format required by the Ministry of Finance.

Therefore, where such solutions are used, the technical aspect is not usually a major challenge. Unfortunately, it is significantly more demanding in the case of taxpayers maintaining accounting books using software imposed by foreign parent companies. Such systems are often only minimally adapted to Polish reporting requirements (and sometimes not adapted at all). In such circumstances, implementing additional software most frequently requires approvals at the group level, which further prolongs and complicates the process of commencing JPK CIT file generation.

As tax advisers with extensive experience supporting international organisations, we therefore recommend assessing from the very beginning whether it is possible to generate and submit JPK CIT files directly from the company’s existing software, or whether it would be more beneficial to use external service providers through accounting outsourcing or reporting services. Companies specialising in these services – such as RSM Poland – can, upon receiving data exported from the company’s systems, convert it into a JPK CIT file and, on the basis of an appropriate power of attorney, submit it to the competent tax authorities on behalf of the taxpayer.

Such an outsourcing solution may be particularly advantageous for taxpayers changing their accounting system during the tax year, especially given that one of the leading ERP software providers currently requires the implementation of a new software version which, in practice, constitutes a change of accounting system and results in the need to carry out numerous system adjustments and harmonisation activities that may prove problematic from a JPK CIT perspective.

Preparing all data required for reporting

The JPK_KR_PD structure requires the reporting of virtually the entire accounting books and their presentation in a structured format.

It is crucial that the reported data be derived directly from the financial and accounting system, because modifications made at the reporting level – if they affect the content of the accounting records – may be regarded as defects in the accounting books.

Review and organisation of the taxpayer’s chart of accounts

An important part of this stage is reviewing the chart of accounts to identify accounts that are not tax-homogeneous (i.e. accounts in which both tax-deductible and non-tax-deductible categories are recorded by the company).

It is also necessary to identify items creating differences between accounting and tax results, as well as off-balance-sheet events affecting the current tax result (such as hypothetical interest or income arising from free-of-charge benefits). The method of mapping and recording such business events in the accounting books must then be determined so that, following data export, the tax result can be reconciled with the CIT calculation.

Unfortunately, this may require the introduction of additional analytical accounts.

Assignment of accounting tags required by JPK structures

Another essential step in preparing data for JPK CIT submission is the proper assignment of tags used within the Standard Audit File structures.

The legislator has prepared seven groups of JPK CIT accounting tags (completed in fields S_12_1 and S_12_2), but in practice most taxpayers will use only the set of tags intended for so-called “other entities”.

Some software providers offering solutions prepared for JPK CIT implementation supply chart-of-account structures with tags already assigned. In such cases, taxpayers should verify the correctness of those assignments and ensure that each balance-sheet and profit-and-loss account has been assigned the appropriate accounting tag.

It should be remembered that, in order to assign the correct tag, attention should be paid to the nature of the transactions recorded in the account rather than merely to the account description or its placement within the balance sheet or profit and loss account.

The final step in preparing the data is the assignment of tax tags in field S_12_3. These tags are dedicated to profit and loss accounts and off-balance-sheet accounts whose balances affect the reconciliation between accounting and tax results.

We therefore recommend standardising data mapping principles to minimise the risk of inconsistencies between JPK CIT files and the CIT calculation.

Test reporting and trial submission of JPK CIT files

After collecting and preparing the data required under the new regulations and ensuring that the ERP system is ready to submit JPK CIT files, it is advisable to conduct test reporting.

Such testing may be performed using a smaller volume of data, for example data from a single month. The test report, generated in XML or Excel format, should also be visualised using available testing tools to identify any inconsistencies. 

The most common errors identified during JPK CIT testing include:

• discrepancies in balance totals (for example, resulting from one-sided postings to off-balance-sheet accounts), 
• breaks in data continuity, 
• incorrect dates, 
• gaps in the journal, 
• missing transaction descriptions. 

Testing helps taxpayers assess whether changes to system settings are required (and whether such changes will be sufficient to export data correctly from the system and report it in the required format), or whether the non-compliance of the Standard Audit File results from deficiencies in the entity’s bookkeeping practices.

Verification of the consistency of data covered by the JPK CIT obligation

An important aspect is maintaining data consistency – not only within the JPK CIT file itself (i.e. between data presented in specific nodes, such as account balances), but also between JPK CIT and other tax or accounting reports.

First, the generated JPK CIT file should be compared with the CIT tax calculation. Although tax tags and the income tax settlement node (which is optional for 2025) do not necessarily have to reconcile fully with the tax result, it is worthwhile analysing the consistency of their individual components. 

The consistency of the JPK CIT file with the data presented in the financial statements should also be verified. Using the assigned tags, a taxpayer may generate a balance sheet or profit and loss account and compare them against the financial statements.

It should be remembered that, based on the data submitted in the Standard Audit File for CIT, tax authorities will be able to automatically verify other tax-related issues, including:

• WHT taxation, 
• transfer pricing, 
• domestic minimum tax, 
• shifted profits tax, 
• R&D tax relief settlements,
• IP Box tax relief settlements. 

With this in mind, it is advisable to review settlements relating to these areas in advance and compare their results with the data reported to the Polish tax authorities through JPK CIT.

JPK CIT implementation should be approached with a high degree of caution

Implementing JPK CIT reporting requires companies to commit considerable resources and engage specialists from various disciplines, including accounting, tax and IT. With this in mind, we provide our clients with comprehensive support at every stage of the implementation process – from technical preparation and data consistency verification to tag assignment.