Recording sales on a cash register (kasa fiskalna) requires particular care and precision. Even the most experienced cashiers can still make mistakes while serving customers. Polish tax law allows such errors to be corrected, but the whole process has to be properly documented. The log of obvious errors on a cash register is a key part of the system for controlling and documenting mistakes made when recording sales.
Keeping this log correctly not only ensures compliance with tax law, but also reduces the risk of negative consequences of a tax inspection. Every obvious error must be properly documented, corrected and reflected in the tax settlements.
What obvious errors on a cash register are
Obvious errors on a cash register are mistakes made when recording sales that have specific features distinguishing them from deliberate manipulation or intentional actions. Although tax law does not contain a precise definition of an obvious error, accounting practice has developed clear criteria for identifying one.
An obvious error must be indisputable, unintentional and clearly the result of inaccuracy or haste while operating the cash register. Such a mistake should be visible at first glance and must not require detailed explanations of why it occurred
The first characteristic of an obvious error is that it is indisputable. The mistake must be so obvious that there is no doubt about its unintentional nature. Examples include entering the wrong amount because digits were mixed up, choosing the wrong VAT rate for a product, or recording a sale in the wrong product category.
The second key feature is that the error is unintentional. An obvious error must result from genuine human error, not from a conscious attempt to manipulate sales data. Such mistakes most often happen because the cashier is in a hurry while serving customers, is tired or distracted, or simply mistypes data into the cash register.
The third feature is that the error is evident and results from inaccuracy. The mistake should be so obvious that anyone reviewing the sales documents can easily spot it. One example is recording a sale of bread at the 23% VAT rate instead of the correct 5% rate, or entering PLN 1,000 instead of PLN 10 for a small item.
Being visible at first glance means that the error does not require detailed analysis or comparison with other documents. An obvious error should be immediately recognisable to anyone who knows the basics of operating a cash register and the specifics of the products being sold
The last key feature is that no detailed explanations are needed. An obvious error should be clear enough on its own not to require any additional justification or detailed description of how it happened. A short note on the nature of the error and how it occurred is enough.
Typical obvious errors include entering the wrong quantity of goods, confusing product codes with similar names, applying the wrong VAT rate, recording a sale in the wrong product category, entering an incorrect unit price, or accidentally recording the same transaction more than once.
Legal obligations for correcting errors
Under current tax law, taxpayers who use cash registers have clearly defined obligations for correcting obvious errors. The main legal act governing this issue is the Regulation of the Minister of Finance of 25 June 2025 on cash registers (Journal of Laws (Dz.U.) 2025, item 845, in force since 1 July 2025), which in § 3 sections 4 and 5 sets out what to do when errors occur while recording sales.
The taxpayer must correct an obvious error made when recording a sale on a cash register without delay. Delays in correcting errors may have negative consequences during tax inspections and affect the accuracy of VAT settlements
The obligation to correct errors without delay means that the taxpayer should react to errors as soon as possible after identifying them. The regulation does not set a deadline in days; in practice, it is recommended to correct the error on the day it is discovered or, at the latest, on the next working day.
A key element of the correction procedure is keeping proper documentation. The taxpayer must keep a log of obvious errors in which all errors found and their corrections are documented in detail. This log is the basis for settling VAT correctly and serves as evidence in any tax inspection.
Correcting an error involves several steps. The first step is to identify the error and record it in the log of obvious errors. Next, you attach to the log the original fiscal receipt (paragon fiskalny) confirming the incorrect transaction or, for electronic receipts, enter the receipt number and the unique number.
- Identify the obvious error while reviewing sales
- Enter the error in the log of obvious errors with a description of the circumstances
- Attach the original fiscal receipt or enter the number of the electronic receipt and the unique number of the cash register
- Record the sale again on the cash register at the correct amount
- Update the accounting records to reflect the correction
- Include the correction in the VAT settlement for the relevant period
Once the error has been documented in the log, the taxpayer should record the sale on the cash register again, this time at the correct amount. This additional entry on the register corrects the wrong data and ensures that the final settlements are accurate.
The regulations do not specify any particular form for the log of obvious errors, so it can be kept in a traditional notebook, on printed forms filed in a binder or electronically. What matters most is that the entries are clear, chronological and complete
In practice, the most common form of the log is a traditional notebook with numbered pages or ready-made forms available in office supply shops. Some business owners keep the log electronically, which is also acceptable, provided that the data is properly secured and the records can be printed at the request of the inspection authorities.
Template for a log of obvious errors
A properly kept log of obvious errors on a cash register must contain all the elements required by tax law. Although the regulation does not prescribe a fixed template for this log, practice has developed standard elements that should appear in every error register.
The basic elements of the log include the business owner’s identification details, the number and model of the cash register, the period covered by the log and detailed information about each recorded error. Each entry in the log should be numbered and dated, which keeps the documentation chronological and clear.
The log of obvious errors must contain the incorrectly recorded sale, stating the gross sales value and the amount of output VAT. It must also include a short description of the cause and circumstances of the error, together with the original fiscal receipt attached
The header of the log should contain basic identification details. These include the taxpayer’s name or full name, the business address, the NIP (tax identification number) and the identification number of the cash register. It is also important to state the period covered by the log, which is usually one month.
The main part of the log is a table with detailed information about each error. The first column should contain the entry number, the second the date of the error, and the third the fiscal receipt number and, for electronic receipts, also the unique number of the cash register.
| No. | Date | Receipt no. | Gross value | VAT | Description of error | Correction |
|---|---|---|---|---|---|---|
| 1 | 15 July 2025 | 0045/2025 | PLN 123.00 | PLN 23.00 | Wrong VAT rate for bread | Recorded again at 5% VAT |
| 2 | 18 July 2025 | 0067/2025 | PLN 1,000.00 | PLN 186.99 | Wrong amount – PLN 1,000 entered instead of PLN 10 | Correct amount recorded |
| 3 | 22 July 2025 | 0089/2025 | PLN 45.50 | PLN 8.51 | Same transaction recorded twice | Duplicate deducted |
The remaining columns should contain the gross value of the incorrectly recorded sale, the amount of VAT charged in error, a detailed description of the cause and circumstances of the error, and information on how it was corrected. In the examples, the incorrect sale was recorded at the 23% rate, and VAT is calculated from the gross amount using the tax-inclusive method: gross × 23/123 (at the 8% rate it would be gross × 8/108).
The description of the cause should be brief but precise, so that the nature of the error is easy to understand. Examples include applying the wrong VAT rate, a mistake in the sale amount, recording a transaction twice or choosing the wrong product code
At the bottom of each page of the log, it is a good idea to include a summary showing the total value of incorrectly recorded sales and the total amount of VAT charged in error. At the end of the month, it is worth preparing a summary of the whole log, which will be used to correct the revenue shown in the cash register’s periodic report.
The monthly summary should contain the total value of all errors broken down by VAT rate, which makes it easier to enter the corrections in the tax return. It is also worth including the number of errors recorded and their percentage share of total sales, which can be used to analyse the quality of cash register operation. If errors keep recurring, it is worth checking the device itself – we write separately about how a cash register technical inspection works.
Documenting errors in practice
Documenting obvious errors on a cash register in practice requires systematic procedures that make the log complete and reliable. The first step is to appoint a person responsible for keeping the log, who should be properly trained in identifying errors and keeping the documentation.
The most important element of documenting errors in practice is regularly checking the fiscal receipts issued. This check should be done daily, ideally at the end of the working day, when the cashier can calmly review all transactions. During the check, look out for unusual amounts, wrong VAT rates, duplicate entries and other irregularities. Receipts for advance payments need separate attention – the rules are set out in our article on the fiscal receipt for an advance payment.
Once an obvious error is found, it should be entered in the log immediately, together with an exact description of the circumstances in which it occurred. Delays in documenting errors can make it harder to establish their causes later and to make the corrections properly
The documentation process starts with an accurate description of the nature of the error. The description should state the type of error, its cause and the circumstances in which it occurred. For example, if the error concerns the wrong VAT rate, the description should state which rate was applied by mistake and what the correct rate should be.
The next step is to secure the evidence. For paper receipts, attach the original receipt to the log, ideally by sticking it to the relevant page or placing it in a clear plastic sleeve. For electronic receipts, it is enough to enter the receipt number and the unique number, but it is also worth making a printout or screenshot for documentation purposes.
- Daily check of issued fiscal receipts for errors
- Immediate documentation of errors found in the log
- Attaching original receipts or entering unique numbers
- Detailed description of the causes and circumstances of each error
- Monthly summaries for settlement purposes
- Archiving the log in line with the rules on document retention
Keeping the log in practice also requires correction procedures. Once an error has been documented in the log, the correction should be made without delay by recording the sale again at the correct amount. This correction should also be noted in the log, stating the number of the new fiscal receipt. Similar questions about when to print a receipt arise with payments received after hours.
Monthly summaries of the log of obvious errors should be prepared in time for the corrections to be included in the VAT return for the relevant settlement period. It is best to prepare the summary by the 15th of the month following the settlement period
Training the staff who operate the cash register is another important practical aspect. Employees should be familiar with the most common errors, the procedures for detecting them and the obligations for documenting them. Regular training can significantly reduce the number of errors made.
A retail company employing three cashiers introduced a procedure in which the shop manager checks receipts every day. As a result, the number of unnoticed errors fell markedly, and preparing the monthly summary of the log took much less time.
How often to keep the log
Choosing the right period for the log of obvious errors on a cash register is crucial for settling VAT correctly and complying with tax law. Although the regulations do not clearly specify a particular period for the log, accounting practice has developed certain standards linked to taxpayers’ settlement periods.
The basic rule is to align the log period with the taxpayer’s VAT settlement period. This means that taxpayers who settle VAT monthly should keep a monthly error log, while those who settle quarterly can keep a quarterly log.
It is generally accepted that the log of obvious errors on a cash register should be drawn up for the settlement period in which the taxpayer settles VAT. This allows the corrections to be properly included in the relevant tax return
In practice, however, the most common solution is to keep a monthly log of obvious errors, regardless of the taxpayer’s settlement period. This is because revenue from the cash register is recorded on the basis of the periodic (monthly) fiscal report, which the taxpayer issues for each month by the 25th of the following month.
A monthly error log has several practical advantages. Firstly, it allows you to check regularly that sales are recorded correctly and to detect errors quickly. Secondly, it makes it easier to make corrections in the accounting records and tax returns. Thirdly, it makes the documentation clearer and makes any inspections easier. We record such corrections in VAT records and JPK files as part of our accounting services.
Taxpayers who settle VAT quarterly but decide to keep a monthly error log must remember to add up the corrections from three months when preparing the quarterly VAT return. In this case, an additional quarterly summary can be helpful.
A summary of the log at the end of each month allows the taxpayer to correct the revenue shown in the periodic report for that period. This is particularly important when preparing the VAT return and when recording sales revenue
Some taxpayers, especially those with low sales volumes, may consider keeping a weekly or even daily error log. This can be justified if errors occur very often or if the nature of the business requires particularly precise control of sales.
Whatever period you choose, it is essential to keep the log consistently. Any change of period during the tax year should be justified by objective reasons and properly documented. It is best to set the period at the beginning of the year and stick to it.
Another practical solution is to keep the log separately for each cash register if the business uses more than one. Although the regulations do not require this, it can make it easier to check and analyse errors made by individual cashiers or at individual checkouts.
Recording corrections from the error log in the accounts
Correctly recording corrections from the log of obvious errors on a cash register is an important part of a company’s accounting system. These corrections directly affect the amount of sales revenue, the amount of output VAT and the accuracy of the financial statements.
The basis for recording the corrections is the monthly summary of the log of obvious errors. This summary should contain the total value of incorrectly recorded sales broken down by VAT rate and the total amount of VAT charged in error. On this basis, the accountant can make the appropriate correcting entries.
Corrections for obvious errors are recorded as a reduction of sales revenue and a reduction of output VAT. These amounts are entered in the accounting system as negative values, preceded by a minus sign
The process starts with preparing an accounting document based on the summary of the error log. This document should contain a detailed description of the correction, the period it relates to and the correction amounts broken down into net value, VAT and gross value.
In accounting systems, these corrections are entered as corrections (reductions) of sales revenue, not as other revenue. It is important to enter the correction amounts as negative values, which reduces the total revenue and output VAT for the period.
A typical accounting entry for error corrections is a red reversal (storno czerwone), i.e. negative amounts on the same sides of the accounts as the original sale: the net value with a minus sign on the credit side of the sales revenue account, the tax with a minus sign on the credit side of the output VAT settlement account, and the gross value with a minus sign on the debit side of the account where the sales proceeds were recorded (e.g. cash). This entry reduces revenue and the VAT liability.
- Prepare the monthly summary of the error log
- Draw up an accounting document based on the summary
- Enter the correction in the accounting system as negative values
- Update the VAT sales register to reflect the corrections
- Check that the account balances are correct after the corrections
- Include the corrections in the VAT return for the relevant period
Pay particular attention to reflecting the corrections correctly in the VAT sales register. Error corrections should be entered as negative items, with a description indicating that they come from the log of obvious errors.
The RO marker in the JPK_V7 file (VAT return with records, SAF-T file) is not a category for error corrections. It marks a summary proof of sales from cash registers, i.e. sales resulting from the cash register reports. A correction from the log of obvious errors reduces the sales shown in the VAT records on that basis
A practical solution is to keep a separate analytical account for corrections of obvious errors. This makes it easy to identify and analyse the scale of errors made on cash registers and to assess how effective the control procedures are.
When recording corrections, also remember their effect on other areas of reporting. Error corrections can affect the income tax base, so it is important to reflect them correctly in the revenue and expense records.
A company running a chain of retail shops entered corrections for obvious errors at the end of each month. Thanks to recording the corrections systematically, it was able to identify the cash register on which errors were made most often, which allowed it to run additional training for the staff and significantly reduce the number of errors.
