Today's labour market is shaped by dynamic structural changes resulting from restructuring, mergers and acquisitions. In this context, issues related to the transfer of an undertaking (przejście zakładu pracy) and the resulting obligations towards ZUS (Social Insurance Institution) become particularly important. The transfer of an undertaking is governed by Article 23(1) of the Labour Code (Kodeks pracy), which provides that employment relationships pass to the new employer by operation of law, ensuring continuity of employment and protection of employee rights.
Alongside the transfer of an undertaking comes the key issue of the obligation to file ZUS IWA, the information needed to set the accident insurance contribution rate. This obligation is fundamental to the proper functioning of the social insurance system and has a direct effect on the cost of running a business.
A transfer of an undertaking under Article 23(1) of the Labour Code means that the new employer automatically steps into the existing employment relationships by operation of law. This rule is mandatory and cannot be modified by agreement between the parties, ensuring full protection of employee rights
The transfer of an undertaking in the context of ZUS IWA obligations needs a detailed analysis, because the new employer must meet certain conditions to be required to file this information. These conditions are: being registered with ZUS without interruption as a payer of accident insurance contributions throughout the previous year and for at least one day in January, reporting an average of at least 10 people a month for accident insurance, and being entered in the REGON register (statistical number register) on 31 December of the previous year (Article 28 sections 2–3 and Article 31 section 7 of the Accident Insurance Act). We handle ZUS registrations and personnel records of transferred employees as part of our HR and payroll services.
Legal basis for the transfer of an undertaking
The Labour Code provisions are the foundation of employee protection when the employing entity changes. Article 23(1) of the Labour Code states precisely that when an undertaking or part of it is transferred to another employer, the new entity becomes a party to the existing employment relationships by operation of law. This rule aims to ensure continuity of employment while preserving all existing employee rights, which is an important safeguard for employees in restructuring processes. If there are no company trade unions at the employers, the current and new employer must inform employees on paper or electronically about the date, reasons and consequences of the transfer at least 30 days before the planned date (Article 23(1) § 3 of the Labour Code).
The practical importance of this provision is huge, because a change of business owner does not terminate employment contracts or interrupt periods of employment. This means employees keep all their acquired rights, including length of service, the right to annual leave, the level of pay and other benefits under their employment contracts. This rule is mandatory and cannot be modified by agreement between the parties, which protects employees against attempts to get around the protective provisions.
Article 23(1) of the Labour Code applies only to employees. For people employed on a basis other than an employment contract (e.g. appointment, nomination), the new employer must propose new terms of work and pay on the day of the transfer (Article 23(1) § 5 of the Labour Code). For people working under civil-law contracts, such as a contract of mandate (umowa zlecenia) or a contract for specific work (umowa o dzieło), the protection under this provision does not apply
Another important element is Article 23(1) § 2 of the Labour Code, which introduces joint and several liability of employers when part of an undertaking is transferred. The current and new employer are then jointly and severally liable for obligations under employment relationships that arose before the transfer. This protection gives employees confidence that a change of employer will not affect the benefits they are owed, such as pay, social benefits or other obligations under their employment contracts.
The rules on the transfer of an undertaking cover a wide range of legal and economic situations. They may apply to the sale of a business, mergers of companies, division of a business, ownership transformations or other forms of reorganisation. What matters is that an organised whole or part of a business is actually taken over and retains its economic identity.
Effects of the transfer of an undertaking under Article 23(1) of the Labour Code
The transfer of an undertaking has a number of significant legal consequences that affect every aspect of employment relationships. The new employer automatically steps into the existing employment relationships without having to sign new contracts or go through any recruitment formalities. Employees who worked for the previous employer remain employed on exactly the same terms as before the transfer.
This automatic transfer of employment relationships guarantees continuity of employment, which in practice means that periods of employment, acquired rights to annual leave, additional leave, bonuses, awards and other entitlements continue without any interruption. The new employer cannot unilaterally change the terms of employment, pay or other elements of the employment relationship without following the procedures set out in the Labour Code. What then happens to saving in employee capital plans is explained in our article on PPK when the employer restructures.
A transfer of an undertaking may concern a whole organisational unit or only part of it. When part of an undertaking is transferred, it is essential to establish which employees are directly linked to the transferred part and what specific terms of employment will apply after the transfer
In business practice, companies often decide on partial transfers as part of restructuring, mergers or spin-offs of certain departments. In such cases it is particularly important to define the scope of the transfer precisely and identify the employees affected by the change of employer. The transfer of an undertaking or part of it cannot be a reason for the employer to terminate an employment relationship with notice (Article 23(1) § 6 of the Labour Code), and any change to terms of work or pay requires the Labour Code procedures to be followed.
Another significant consequence of the transfer of an undertaking is the employees' special right to end the employment relationship in a simplified procedure. The provision states that within 2 months of the transfer date an employee may terminate the employment contract without notice, giving 7 days' warning (Article 23(1) § 4 of the Labour Code). This right is an important tool for protecting employees' interests, especially where the new terms of employment, organisational culture or development prospects do not meet their expectations.
Terminating the contract in this way has the same consequences for the employee as the employer terminating the contract with notice under labour law, which means the employee is not treated as if they had resigned. This rule lets employees decide freely whether to continue working for the new employer, which matters, among other things, when later applying for unemployment benefit.
Transfer of an undertaking and ZUS IWA – requirements and obligations
Filing ZUS IWA in connection with the transfer of an undertaking is one of the most complex aspects of the process. ZUS IWA, the information on data used to set the accident insurance contribution, is used to determine the accident insurance contribution rate for the coming contribution year. The mechanism is designed to match the contribution to the actual level of hazards at a given workplace.
The Accident Insurance Act sets out precisely the conditions contribution payers must meet to be required to file ZUS IWA. Under the current rules, the obligation applies to payers who meet all of the following criteria:
- They were registered with ZUS as a payer of accident insurance contributions without interruption for all months of the previous calendar year and for at least one day in January of the current year (Article 31 section 7 of the Accident Insurance Act)
- In the previous calendar year they reported an average of at least 10 people a month for accident insurance, including themselves if they run a business (Article 28 sections 2–3)
- On 31 December of the previous year they were entered in the REGON register
ZUS clearly stresses that payers who, for even one month of the previous year, were not payers of the accident insurance contribution – because no person for whom they paid contributions was covered by that insurance – do not have to file ZUS IWA
In the context of a transfer of an undertaking, pay particular attention to continuity of insurance registrations. When the new employer takes over employees under Article 23(1) of the Labour Code, it also becomes the payer of accident insurance contributions for those employees. Continuity of registrations is crucial, because any break in the process may mean that the payer is no longer required to file ZUS IWA.
The ZUS IWA obligation is annual, and the filing deadline is the last day of January of the year following the year the information covers (Article 31 section 6 of the Accident Insurance Act). In the case of transformation, merger or division of payers, succession rules do not apply to the accident insurance contribution rate (Article 27 section 2), so the new payer does not take over its predecessor's rate. The data submitted in this document form the basis for setting the accident insurance contribution rate, which has a direct effect on the company's cost of doing business. How the other contributions are split between employer and employee is shown in our piece on ZUS contribution rates for employees.
A transfer of an undertaking neither changes nor removes the conditions that determine whether ZUS IWA must be filed. The new employer must meet all the requirements of the Accident Insurance Act to be subject to this obligation, regardless of having taken over employees from the previous employer
Practical aspects of completing ZUS IWA after taking over employees
Completing the ZUS IWA form after taking over employees from another employer requires particular care and precision. In ZUS IWA the payer submits its own data for the calendar year (Article 31 sections 3 and 5 of the Accident Insurance Act): the number of insured persons it registered itself in the individual months, persons injured in accidents recorded in its accident register and the number of employees working in hazardous conditions. This rule follows from the fact that the contribution rate is meant to reflect working conditions and hazards at the payer in question.
The key items to include when completing ZUS IWA after taking over employees fall into the following categories:
| Form item | Scope of data | Period covered | Special notes |
|---|---|---|---|
| Number of insured persons | Persons registered by the payer | Average of the 12 months of the year | Transferred employees are counted from the month the payer registered them |
| Injured persons | Accidents at work recorded in the payer's accident register | Calendar year (date of recording) | Accidents before the transfer were, as a rule, recorded by the previous employer |
| Hazardous conditions | Employees in positions where NDS/NDN limits are exceeded | As at 31 December | Employees only |
| Accident contributions | Registration as a contribution payer | Without interruption all year and at least 1 day in January | Condition for the obligation to file IWA |
The number of insured persons on the form is the average number of people the payer registered for accident insurance in the individual months of the calendar year (the monthly total divided by 12, rounded to a whole number). This means you include both existing employees and those transferred with part or all of the business – but the transferred employees only from the month in which the new employer registered them as their payer. This method of counting serves to set the accident insurance contribution rate correctly.
On the ZUS IWA form, enter the number of persons injured in accidents at work recorded in the payer's accident register in the given calendar year (by date of recording). Accidents recorded by the previous employer before the transfer are, as a rule, reported by that employer in its own information
A special category is data on employees working in hazardous conditions, i.e. people working in an environment where permitted concentrations and intensities of agents harmful to health are exceeded. The form shows the number of such employees as at 31 December of the year the information covers – which includes transferred employees working in such positions on that day.
ZUS position on the transfer of an undertaking
The position of ZUS on completing ZUS IWA follows from the ZUS guide to this form and draws an important distinction in how data are reported. Under it, ZUS IWA includes accidents recorded by the payer filing the information in the year it covers. The number of people working in hazardous conditions is given as at 31 December, counting only that payer's employees.
According to ZUS, the information in ZUS IWA should reflect the actual working conditions at the given workplace as accurately as possible. For this reason, reporting data on events at the previous contribution payer may not directly reflect working conditions at the new workplace. This interpretation is meant to ensure that the accident insurance contribution rate corresponds to the actual level of hazards in a specific working environment.
The law does not expressly regulate how data from before the transfer should be shown in ZUS IWA after a transfer of an undertaking. Given how complex the issue is, it is worth approaching each case individually and considering all the elements that affect the accident contribution rate
How these data are reported matters in practice, because it may affect the accident insurance contribution in the following year. If you are unsure how to complete ZUS IWA correctly, it is advisable to consult a tax adviser or a lawyer specialising in labour and social insurance law.
The practical implications of these rules can be illustrated with specific examples. A newly formed company that, under a business agreement, took over employees of another company under Article 23(1) of the Labour Code from June 2026 does not have to file ZUS IWA for 2026, because it was not a contribution payer for the whole calendar year. In this case, not being registered as a payer without interruption for the whole year removes the obligation to file the information. It pays to get the registrations themselves right regardless of IWA – the effects of mistakes are described in our article on ZUS registration without a contract.
Analysis of practical cases
The variety of situations involving the transfer of an undertaking means each case needs an individual approach. Business practice shows that a transfer can take different forms and happen at different points in the calendar year, which has a direct effect on ZUS IWA obligations.
Take the example of a workplace that had employed 5 employees for several years and from 1 July 2026 took over some employees of another workplace, gaining 9 additional employees. In this case the workplace meets all the conditions for filing ZUS IWA for 2026 (assuming it is entered in REGON), because it was a payer of accident insurance contributions throughout the year, and the average number of insured persons registered – (6 × 5 + 6 × 14) : 12 = 9.5 – reaches the required 10 people after rounding. When completing the declaration, include all employees – both existing staff and the newly transferred ones (from the month of the transfer).
Another example is when a large company decides to spin off a department into a separate company. If the new company is set up during the year and takes over employees under Article 23(1) of the Labour Code, whether it must file ZUS IWA depends on meeting all the statutory conditions. What matters here is uninterrupted registration as a contribution payer for all months of the calendar year.
Practical example: A manufacturing company employing 50 people decided in October 2026 to spin off its logistics department into a separate company, transferring 15 employees to it. The new company took over the employees under Article 23(1) of the Labour Code, but because it only started operating in October, it does not meet the condition of uninterrupted registration as a payer for all months of the calendar year, which means it does not have to file ZUS IWA for 2026.
When an undertaking is transferred during the calendar year, continuity of insurance registrations and contribution payments is crucial. Any break in these obligations may mean you are not required to file ZUS IWA for that year
Pay particular attention to situations where the transfer of an undertaking happens towards the end of the calendar year. In such cases the new employer may not meet the condition of uninterrupted registration as a contribution payer for all months of the year, which automatically removes the obligation to file ZUS IWA. At the same time, it must prepare to meet this obligation in the following year if it meets all the required conditions.
Administrative procedures and documentation
A transfer of an undertaking in the context of ZUS IWA obligations requires a series of administrative steps to ensure continuity of social insurance and proper handling of contributions. The new employer must make sure it takes over all employment and social insurance records of the transferred employees.
The process involves the following key stages:
- Taking over the personnel records of all employees covered by the transfer
- Checking the insurance status of each transferred employee
- Making the relevant ZUS registrations connected with the change of contribution payer
- Reviewing and updating data on working conditions and occupational hazards
- Preparing the documentation needed to complete ZUS IWA for the current year
Continuity in documenting working conditions is particularly important, especially conditions involving exposure to agents harmful to health. The new employer must take over complete documentation of preventive medical examinations, health and safety (BHP) training, occupational risk assessment and any other elements affecting the accident insurance contribution rate.
A key part of the transfer is an inventory of all health and safety events that occurred in the transferred workplace or part of it. These data will be needed to complete the ZUS IWA form correctly
In practice, a transfer of an undertaking often requires cooperation between the previous and the new employer to hand over complete documentation. It is particularly important to obtain information on all accidents at work, occupational diseases and other events that may affect the accident insurance contribution rate in the following year.
Impact on the cost of doing business
A transfer of an undertaking and the related ZUS IWA obligations have a direct effect on the cost of doing business. The accident insurance contribution rate is set on the basis of the data in ZUS IWA and can vary significantly depending on the level of hazards at a given workplace. Business owners planning to take over an undertaking should include this aspect in the economic analysis of the whole process.
The accident insurance contribution can vary widely depending on the industry, the type of work and the accident history of a given workplace. Companies with a high level of workplace safety may benefit from lower contribution rates, while workplaces with a higher accident risk must expect higher insurance costs.
- Analysis of accident risk at the workplace being taken over
- Assessment of the history of accidents and occupational diseases
- Review of the personal and collective protective equipment used
- Verification of the effectiveness of health and safety management systems
- Planning investment in improving workplace safety
When an undertaking is transferred, it is particularly important to carry out a reliable assessment of health and safety at the workplace being taken over. The new employer should carry out a comprehensive health and safety audit to identify potential hazards and plan measures to improve working conditions and reduce the risk of accidents.
Investment in improving workplace safety after a transfer can bring long-term benefits in the form of lower accident insurance contributions. Systematic preventive measures can significantly reduce the contribution rate in the following years
