Business inspections in Poland in 2026: how tax and social security authorities use AI and risk analysis

Business inspections in Poland in 2026 are increasingly targeted at companies whose data indicates a higher risk of non-compliance. Between January and August 2026, the Social Insurance Institution (ZUS) identified irregularities in 90.1% of its inspections, with financial findings totalling PLN 373.3 million. In 2025, the National Revenue Administration (KAS) reduced customs and fiscal audits by 27.4% and tax audits by 11.3%, while increasing preliminary verification activities by 9.6%. Electronic reporting, automation and analytical tools are changing how authorities identify reporting errors and tax fraud. Data published by ZUS and KAS demonstrates the growing importance of risk-based inspection and audit selection, enabling authorities to identify irregularities more effectively and concentrate resources on areas requiring closer examination. For businesses, accurate reporting, consistent data and reliable evidence of actual transactions are becoming essential.

Business inspections in Poland in 2026 reflect a significant shift in how public authorities oversee corporate compliance. Both ZUS and KAS are making greater use of data analysis and risk assessments to identify businesses that warrant closer scrutiny.

This does not mean that businesses face less scrutiny across all areas. Although certain types of formal inspections and audits are declining, data analysis, automation and preliminary verification procedures are becoming more important. As artificial intelligence develops, authorities are gaining greater opportunities to identify irregularities using information from different systems. This applies both to errors in corporate reporting and to tax fraud, including fictitious transactions and unreliable invoices.

For company boards, CFOs and professionals responsible for accounting and HR, compliance increasingly requires not only meeting statutory obligations but also systematically checking the accuracy of information submitted to Polish public authorities.

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Business inspections in Poland – Fewer checks, more effective enforcement

The latest available figures from both institutions indicate that inspection and audit selection is becoming more targeted. ZUS reports a high proportion of inspections resulting in identified irregularities, while KAS is recording higher financial findings despite conducting fewer formal audits.

Indicator	Result	Period
ZUS inspections	20,529	January–August 2026
ZUS inspections identifying irregularities	90.1%	January–August 2026
Financial findings from ZUS inspections	PLN 373.3 million	January–August 2026
Number of KAS customs and fiscal audits	Down 27.4%	2025 vs 2024
Financial findings from customs and fiscal audits	Up 46.4% to PLN 6.52 billion	2025 vs 2024
Number of tax audits	Down 11.3%	2025 vs 2024
Number of KAS preliminary verification activities	Up 9.6%	2025 vs 2024

These figures cover different periods and types of proceedings and should not be directly compared as a single measure of inspection or audit effectiveness. Nevertheless, they indicate a common trend: Polish authorities are increasingly concentrating their resources on areas of identified risk.

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ZUS inspections in Poland in 2026 – Irregularities in over 90% of cases

In an announcement published on 6 October 2026, ZUS presented the results of inspections carried out between January and August 2026. During this period, it conducted 20,529 inspections of contribution payers, identifying irregularities in 18,495 cases. This represents a detection rate of 90.1%. In 15,697 cases, the irregularities had financial implications, with total findings amounting to PLN 373.3 million.

The largest share of these findings concerned incorrectly calculated social insurance contributions, amounting to PLN 360.6 million. The remaining PLN 12.7 million related to the calculation or settlement of social insurance benefits.

ZUS inspection effectiveness – Comparison of 2017 and 2026

In 2017, ZUS conducted more than 60,800 inspections and identified irregularities in approximately 65% of cases. During the first eight months of 2026, this proportion exceeded 90%.

The change is also evident in the average financial findings per inspection. According to ZUS, the figure was approximately PLN 6,000 in 2017, compared with more than PLN 18,000 in 2026.

This does not mean that 90% of all businesses are non-compliant. The figure applies only to entities selected for inspection, a group in which ZUS had already identified potential risk indicators. It is also important to distinguish financial findings from amounts actually recovered. The value of identified irregularities does not automatically equal the amount received by ZUS.

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What irregularities does ZUS most frequently identify?

ZUS highlights problems involving:

• Incorrect assessment of overlapping social insurance obligations arising from multiple insurance titles;
• Understatement of the contribution assessment base;
• Incorrect contribution settlements for individuals performing work for their own employer;
• Use of different contractual arrangements to reduce social insurance contribution liabilities.

These irregularities may concern both the classification of contracts and the calculation of contributions arising from particular insurance obligations. Employers should therefore ensure consistency between contractual terms, employment documentation, actual working arrangements and the information reported in social insurance settlements.

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How does ZUS select businesses for inspections in Poland in 2026?

ZUS uses information held in its own systems, contribution payer data and statistical risk assessment models. These tools help identify businesses where the likelihood of non-compliance is considered higher. The approach is linked to provisions of Poland’s Entrepreneurs’ Law, which require inspections to be planned on the basis of periodic assessments of the likelihood of legal violations.

Which factors increase the risk of a ZUS inspection?

According to information published in the ZUS Public Information Bulletin, the risk assessment framework adopted on 1 January 2026 considers factors including:

• The number of registered insurance policies;
• The type of business activity identified by the Polish Classification of Activities (PKD) code;
• The ratio of benefits paid to contributions due;
• The existence of overlapping social insurance obligations;
• Previous inspection findings and other identified irregularities involving the contribution payer.

Classification into a particular risk category may result from one dominant factor or a combination of several factors.

ZUS does not publish its complete assessment model or the weight assigned to individual variables. Consequently, a company’s industry, workforce size or contribution amounts alone cannot reliably establish its individual probability of being inspected.

ZUS risk categories and inspection frequency in Poland

Polish regulations establish three risk categories that determine the permitted frequency of scheduled business inspections.

Risk category	Permitted frequency of scheduled inspections
Low	No more than once every 5 years
Medium	No more than once every 3 years
High	As frequently as necessary to ensure effective enforcement of the regulations

These limits apply to scheduled inspections. Polish law also provides for specific circumstances in which inspections may be conducted outside the standard schedule.

For businesses, the key consideration is therefore not simply when the last inspection took place, but whether the information submitted to ZUS accurately reflects obligations arising from employment and other social insurance arrangements.

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Tax and customs audits in Poland – Fewer audits, higher financial findings

A similar trend can be observed in the activities of KAS. According to an announcement by the Polish Ministry of Finance on 10 February 2026, KAS conducted nearly 2.64 million activities related to verifying tax compliance in 2025. The total number of activities increased by 9.4% compared with 2024, while financial findings rose by 29.1%, from PLN 14.76 billion to PLN 19.05 billion.

At the same time, the number of formal tax audits and customs and fiscal audits declined.

Customs and fiscal audits in Poland – A 27.4% decline in 2025

In 2025, KAS conducted 5,113 customs and fiscal audits, compared with 7,043 in the previous year. This represents a decrease of 27.4%.

Despite the lower number of audits, financial findings increased from PLN 4.45 billion to PLN 6.52 billion, a rise of 46.4%. Payments associated with customs and fiscal audits increased by 18.5%, from PLN 1.7 billion to PLN 2 billion.

The Ministry of Finance indicates that customs and fiscal audits are increasingly intended to focus on detecting and documenting tax fraud and tax-related criminal offences. Consequently, certain irregularities that do not require such extensive proceedings may be addressed through other procedures.

Tax audits in Poland – An 11.3% decline in 2025

In 2025, KAS conducted 8,722 tax audits, compared with 9,829 in 2024.

KAS links this decline to the increased use of preliminary verification activities. Under the approach described by the administration, authorities should first seek to clarify uncertainties without initiating a formal tax audit where the nature of the case permits.

For businesses, this means that the first indication of an authority’s interest in their tax affairs may be a request for explanations or documents rather than a formal audit.

We provide a detailed breakdown of KAS results for 2025, including the implications of digitalisation and internal procedures, in our article Tax audits by Poland’s National Revenue Administration (KAS): how companies should prepare in 2026.

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What is the difference between preliminary verification activities and a formal tax audit in Poland?

Preliminary verification activities are a separate, less formal procedure provided for under the Polish Tax Ordinance. They allow tax authorities to examine specific aspects of tax compliance, including the timely submission of returns and payment of taxes, the formal accuracy of documents and selected circumstances relevant to tax settlements. They are not equivalent to a full tax audit.

From a business perspective, the main distinction concerns the scope and purpose of the procedures. Preliminary verification activities aim to clarify specific issues, whereas a tax audit formally examines whether a taxpayer has fulfilled obligations under Polish tax law.

Preliminary verification activities – A growing role in Polish tax compliance

Figures for 2025 show that the number of preliminary verification activities increased by more than 228,000, or 9.6%, compared with 2024. Financial findings arising from these activities increased by more than PLN 2.4 billion, representing growth of nearly 28%.

According to the Ministry of Finance, some cases were resolved by clarifying uncertainties with taxpayers and making the necessary corrections, without initiating customs and fiscal audits. This has important implications for how finance departments organise their work. Responding to an official request may require quickly reconstructing transaction histories, reconciling documents and explaining differences between data reported in separate tax filings.

The absence of a formal audit therefore does not mean that tax compliance is not being examined. Businesses should be prepared to substantiate their tax reporting even during preliminary verification activities.

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How is AI-driven data analysis changing tax audits in Poland?

Advances in analytical tools are changing how Polish tax authorities verify corporate tax compliance. The growing volume of electronically submitted data makes it possible to identify discrepancies between tax returns, accounting records and transaction documents without initiating every verification process through a formal audit.

Advanced data analysis, automation and the development of artificial intelligence (AI) technologies create new opportunities to identify irregularities and potential tax fraud. ZUS and KAS are placing increasing emphasis on risk assessments, enabling more targeted inspection and audit selection and closer examination of areas requiring detailed verification. As a result, the effectiveness of selecting businesses for scrutiny and detecting irregularities is becoming more important than the number of formal inspections or audits alone.

What data can indicate potential tax compliance risks?

Electronic records and reporting systems provide Polish tax authorities with information that can be used to verify the consistency of tax settlements. Relevant data includes transactions reported by taxpayers, VAT settlements, information about counterparties and accounting documentation. Analysing these records can help identify inconsistencies requiring further explanation. However, a discrepancy alone does not constitute evidence of tax fraud. Its assessment must take account of the nature of the transaction, applicable legislation and supporting documentation.

The development of Poland’s National e-Invoicing System (KSeF) and electronic tax reporting is increasing the volume of structured information available to the authorities. We discuss how these records may be used, including the importance of JPK_CIT reporting structures for tax compliance monitoring, in our article Tax audits in Poland: how KSeF and JPK_CIT are changing tax supervision.

For businesses, the practical implication is the need to ensure not only that individual tax returns are correct, but also that information remains consistent throughout the reporting process. This is particularly relevant for companies using multiple accounting and finance systems or processing large volumes of documents.

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Fictitious invoices in Poland – KAS detects a 29.2% increase in 2025

Identifying invoices relating to transactions that never actually occurred remains a significant focus of KAS enforcement activities.

According to Ministry of Finance data, 376,800 fictitious invoices with a combined value exceeding PLN 10.9 billion were detected in 2025. Compared with 2024, the number increased by 29.2%, while their total value rose from PLN 8.71 billion. The Ministry states that this was the highest number of fictitious invoices detected since 2017. However, it also notes that audits frequently cover earlier reporting periods. The 2025 figures therefore do not mean that all the identified irregularities originated during that year.

Tax and social insurance fraud – A 2026 KAS investigation

A case uncovered by the Mazovian branch of KAS in May 2026 illustrates how irregularities can affect both tax and social insurance settlements. Authorities identified a group of connected businesses operating in the employee outsourcing sector that had used unreliable invoices.

According to KAS findings, the estimated value of these invoices exceeded PLN 91 million, with VAT due amounting to PLN 17 million. The businesses also understated ZUS contributions by unlawfully claiming contribution reliefs and exemptions.

The investigation resulted in 11 customs and fiscal audits. More than PLN 3.6 million was secured through the use of Poland’s STIR bank account blocking mechanism across five accounts. The case demonstrates how tax and social insurance irregularities can arise from interconnected reporting arrangements.

Detecting fictitious invoices through data analysis

Detecting fictitious invoices is an area in which data analysis plays a particularly important role in KAS enforcement activities. Irregularities may involve not only individual documents but also interconnected transactions between multiple entities.

Identifying them often requires examining financial flows, accounting records and relationships between counterparties.

Electronic tax reporting and analytical tools strengthen the authorities’ ability to verify data consistency and identify transactions requiring closer examination. This is particularly relevant to fraud schemes involving multiple connected companies and unreliable documentation.

For businesses, the priority is therefore not only to issue and record invoices correctly, but also to retain evidence confirming that the underlying transactions actually occurred. An invoice appearing in accounting records does not, by itself, establish that a transaction has been correctly reported if the goods or services were never supplied.

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Are certain industries more likely to face ZUS and KAS inspections in Poland?

Data published by the authorities indicates differences between economic sectors. However, operating in a particular industry does not automatically mean that a business will be selected for inspection.

ZUS identifies both sectors where irregularities are frequently detected and industries where identified errors have particularly significant financial consequences.

According to the ZUS announcement of 6 October 2026, irregularities were particularly common in international transport, employment and recruitment services, and security services. ZUS also highlights platform-based work, industries with high employee turnover and businesses making extensive use of civil law contracts.

According to the Ministry of Finance, the sectors most frequently audited by KAS in 2025 included hospitality and food services, construction, automotive repair workshops, beauty services and e-commerce. However, these figures do not establish a ranking of inspection probability for individual businesses. Without considering the number of companies operating in each sector and other risk factors, it is not possible to determine which industry exposes an individual company to the greatest likelihood of inspection.

For businesses, identifying areas of compliance that require particular attention is more important than industry classification alone. For example, a company using multiple employment arrangements should review its social insurance obligations, while a business conducting large volumes of transactions should ensure that the actual substance of those transactions is properly documented.

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What does risk-based inspection and audit selection by ZUS and KAS mean for businesses?

The growing importance of data analysis is changing how businesses should prepare for interactions with Polish regulatory authorities. Correctly calculating and reporting taxes or contributions remains a fundamental obligation, but maintaining documentation that substantiates those calculations is becoming equally important. Not every discrepancy detected by an analytical system indicates a breach of regulations. Differences may arise from legitimate variations in accounting treatment, reporting periods or the nature of a particular transaction.

Nevertheless, businesses must be able to provide appropriate explanations and supporting evidence.

1. How can businesses maintain consistent accounting and tax documentation?

Verifying tax compliance may require comparing tax returns, accounting records, invoices and documents confirming that transactions were completed. Where discrepancies arise, businesses should be able to identify their source and explain the accounting or tax treatment applied. Accuracy involves not only matching figures but also allocating transactions to the correct reporting periods.

2. How can employers ensure accurate payroll and social insurance settlements?

For ZUS compliance, particular attention should be paid to insurance registrations, contribution assessment bases and the classification of different insurance obligations. The risk of errors may increase as employment and remuneration arrangements become more complex, particularly where companies use both employment contracts and civil law contracts.

Regular reviews of these areas, supported by properly managed payroll services in Poland, can help reduce the risk of recurring social insurance reporting errors.

3. How should companies manage internal controls and responsibilities?

In larger organisations, the information used for tax and social insurance reporting originates from different departments. Payroll, purchasing, sales and intercompany transaction data may come from separate systems.

In practice, this requires effective information flows between accounting, HR, finance and employees responsible for approving business transactions. Companies should also establish who is responsible for investigating discrepancies and assembling documentation when an authority requests information.

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How should businesses prepare for a ZUS or KAS inspection in Poland?

Preparing for an inspection should not begin only when a formal notification or request arrives. In businesses with complex organisational structures, reconstructing documentation and reporting histories covering several periods may require input from multiple teams.

Companies should therefore periodically review the areas where reporting errors are most likely to occur.

The review should primarily cover:

1. Tax settlements – consistency between accounting records, tax returns and supporting documents, together with the correct allocation of transactions to reporting periods.
2. ZUS settlements – accuracy of insurance registrations, contribution assessment bases, contract classifications and benefit settlements.
3. Transaction documentation – evidence confirming that services were performed and goods delivered, particularly for unusual or high-value transactions.
4. Internal procedures – processes for approving documents, recording corrections and resolving discrepancies between systems.
5. Official correspondence – timely receipt of requests, clearly assigned responsibility for responses and access to the required information.

The scope of such reviews should reflect the company’s size, business activities and the complexity of its reporting obligations.

For international businesses, consistency between information used by the Polish finance team, overseas headquarters and external providers responsible for individual processes is particularly important.

Well-structured accounting services in Poland and tax advisory services in Poland can support the verification of accounting records, documentation and tax settlements.

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Does a lower number of formal inspections and audits mean lower compliance risk for businesses?

No. A reduction in formal inspections and audits does not necessarily mean that Polish authorities are conducting fewer compliance checks.

ZUS figures indicate increasingly effective selection of businesses for inspection. KAS results, meanwhile, show that the reduction in formal tax audits and customs and fiscal audits has been accompanied by an increase in preliminary verification activities. What is changing is primarily how the authorities organise their compliance activities.

In practice, a business may be required to explain specific discrepancies without a formal tax audit being initiated. Where more serious concerns arise, however, the authority may still take action under the relevant statutory procedures.

Importantly, more effective inspection and audit selection does not automatically indicate an increase in the number of violations committed by businesses. A high proportion of inspections resulting in identified irregularities may also reflect more precise targeting of entities selected for examination.

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Business inspections in Poland in 2026 – Key takeaways

Results published by ZUS and KAS indicate a shift in emphasis from the number of formal inspections and audits towards the accuracy of identifying irregularities and the effectiveness of enforcement activities.

The development of analytical tools and digital tax reporting means that compliance checks can increasingly begin with an assessment of information already available to the authorities rather than an on-site inspection. In the age of AI, distinguishing between unintentional documentation errors and activities indicating potential tax fraud is also becoming increasingly important. In both cases, reliable data, evidence of actual transactions and the ability to explain identified discrepancies remain essential.

For ZUS, information relating to employment, social insurance obligations and contribution calculations is particularly important. KAS focuses, among other areas, on tax compliance, identifying unreliable transactions and clarifying discrepancies through preliminary verification activities.

For businesses, this creates a need for systematic quality control of accounting, HR and payroll data. The main objective should not simply be to reduce the likelihood of an inspection, but to ensure that settlements are accurate and can be properly substantiated.

getsix® supports businesses with accounting, tax compliance and HR and payroll administration in Poland. Companies seeking assistance with reviewing processes and documentation in these areas are invited to contact the getsix® team.

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