A tax audit does not have to catch you off guard. Find out what documents to prepare, what rights a taxpayer has, and what mistakes business owners most commonly make.
A notification of a tax audit can cause stress even for business owners who keep their accounting diligently and on time. Yet a well-prepared company has a real advantage – it moves through the procedure smoothly and minimises the risk of unfavourable decisions by the US. In this article you will find practical tips on documents, taxpayer rights, and the most common mistakes that can prove costly. This knowledge is especially important in 2026, when tax authorities have access to an ever-wider range of analytical tools, such as data from KSeF and JPK files.
As a rule, the tax authority is obliged to notify the taxpayer of a planned audit at least 7 days in advance (and no earlier than 30 days before it begins). Receiving a notification is a signal to act, not a reason to panic. During this time it is worth: • Collecting and organising the documentation for the audited period. • Contacting your accounting firm. • Checking the completeness of VAT registers and income and expense records. • Making sure that invoices in KSeF are consistent with the entries in the books. An audit may take place without prior notification only in strictly defined circumstances – for example, when there is reasonable suspicion of a fiscal offence. In all other situations you are entitled to time to prepare.
The scope of documents requested depends on the subject of the audit; however, it is worth compiling the following in advance: 1. Accounting books or the KPiR (from 2026 in the JPK_PKPIR format for selected taxpayers). 2. VAT records and JPK_VAT files for the audited period. 3. Sales and purchase invoices (including data from KSeF). 4. Contracts with counterparties and documents confirming the performance of services. 5. Bank statements linked to the transactions covered by the audit. 6. Payroll and HR documentation, if the audit covers ZUS and PIT settlements for employees. 7. Fixed asset register and intangible assets register. Documents should be sorted chronologically and by subject. Disorganised documentation is one of the most common reasons for an audit being prolonged.
A business owner subject to an audit is not defenceless – the Tax Ordinance grants them a number of rights that are worth keeping in mind. • The right to have a representative (legal counsel or accountant) present during every audit activity. • The right to inspect audit documents and make copies of them. • The right to submit explanations and objections to the audit report. • The right to amend a tax return – even while the audit is ongoing, if an error is identified (this right is however limited after the audit authorisation has been served). • The right to suspend the audit in justified cases. Never sign documents whose content you do not understand. If in doubt, request time to consult your representative.
Even a company that keeps thorough records can run into problems due to procedural or organisational errors. The most common include: • Lack of complete source documentation – receipts, invoices, or contracts have been lost or were never systematically archived. • Inconsistency between data in KSeF, JPK files, and the books – discrepancies automatically generate questions from auditors. • Making hasty explanations without consulting an accountant or adviser. • Ignoring summons or failing to meet set deadlines, which may result in administrative penalties. • Lack of awareness of the limitation period – an audit may cover liabilities from up to 5 years ago, which is why archiving documents for that period is mandatory. Avoiding these mistakes is a matter of both good organisation and systematic cooperation with a professional accounting firm.
An experienced accounting firm is an invaluable source of support at every stage of a tax audit. Before the audit it helps to compile and verify documentation, identifies potential areas of risk, and prepares explanations for any discrepancies. During the audit, the accountant may participate in activities as a representative or provide auditors with requested summaries and printouts. After the audit – they analyse the report, help formulate objections or an appeal if the authority's findings are unjustified. It is worth bearing in mind that in 2026 data from KSeF and uniform audit files (JPK_CIT, JPK_PKPIR) are analysed by tax authorities even before an audit is initiated. Regular verification of data accuracy with your accounting firm significantly reduces the risk of proceedings being launched.
The best audit is one that never happens – or one that concludes with no findings. A few principles of everyday tax risk management: 1. Ensure timely and accurate submission of returns and JPK files. 2. Issue invoices in accordance with KSeF requirements and verify counterparty data in GUS and VIES databases. 3. Archive documents for at least 5 years (in paper or electronic form). 4. Regularly reconcile balances with counterparties and check the consistency of VAT records with returns. 5. Obtain tax rulings when a transaction raises doubts – they provide protection against potential allegations. Systematic work with an accounting firm and up-to-date knowledge of regulations are the best insurance policy against unpleasant surprises from the US.
A tax audit is a procedure that does not have to end negatively – provided you are prepared. Complete documentation, knowledge of your own rights, and efficient communication with your accounting firm are the pillars of safely navigating any audit. If you want to be certain that your company is ready for an auditor's visit, contact Danexis – call +48 780 760 666, write to kontakt@danexis.pl, or visit our office at ul. Braniborska 74/20 in Wrocław. We will be happy to assess the state of your documentation and advise you on what is worth improving.