JMHZ in 2026: New Monthly Employer Reporting and How to Avoid Costly Mistakes

From 2026, Czech employers will be required to submit the new JMHZ (Unified Monthly Employer Report). While it is presented as a simplification, it often means significantly more complex data preparation, stricter registration rules and real financial exposure. This article explains the rollout timeline, the key compliance risks and what HR and payroll teams should do now.

Official promise vs. reality: what JMHZ really is

On paper, the introduction of JMHZ sounds excellent. Instead of approximately 25 different forms for the Czech Social Security Administration (ČSSZ), the Financial Administration and the Labour Office, from 2026 you will submit a single electronic report. The goal is to reduce bureaucracy and eliminate duplicate reporting.

However, do not be misled. In practice, JMHZ is primarily a tool for the state to build a massive database of the labour market and incomes in real time. Even though the submission will be unified, data preparation becomes significantly more complex, as one report may include up to 400 different data fields. In effect, the state shifts the burden of collecting and validating data directly onto employers.

How not to get lost in the timeline and avoid legal breaches

Misinterpreting the rollout timeline is the quickest route to compliance issues. The implementation does not happen in one step, but in three phases with different rules.

• From 1 January 2026: The law is effective, but reporting is not yet submitted. Your key obligation is to start collecting all new, detailed data, even though you will submit it only several months later.
• From 1 April to 30 June 2026: In this hybrid model, you submit live JMHZ reports for April and the following months. At the same time, you submit three separate reports retroactively for January, February and March. Important exception: for registration of employees (Czech citizens), the current deadline of 8 days AFTER the start date still applies.
• 20 May 2026: This is the deadline for submitting the first standard monthly report, for April 2026.
• From 1 July 2026: A new strict obligation begins. You must register each employee in the system BEFORE they actually start performing work.
  
  

Setting up processes correctly in line with this complex schedule is critical. ARROWS lawyers specialise in this area and can prepare internal policies to ensure your company meets all statutory deadlines. For an immediate solution tailored to your situation, contact us at office@arws.cz.

FAQ – Legal tips on the JMHZ rollout timeline

• What exactly does retroactive reporting for Q1 2026 mean?
  It means that although you submit the reports only in Q2, you must collect and record the underlying data from 1 January 2026. This is a “hidden” administrative burden that employers must plan for.
• Do I have to submit the old reports as well as the new report for January 2026?
  No. The old insurance contribution reports for January to March 2026 will no longer be submitted. Instead, you will submit three separate JMHZ reports retroactively between April and June 2026.
• What happens to the Pension Insurance Record Sheets (ELDP)?
  In standard cases, the obligation to submit ELDP for 2026 onwards will cease. ČSSZ will compile them from the data in JMHZ. ELDP for 2025 will be submitted for the last time in 2026.
• How does employee registration differ before and after 1 July 2026?
  Until 30 June 2026, Czech citizens remain subject to the current 8-day deadline after starting work. From 1 July 2026, you must register employees before they start working. This change requires adjustments to hiring and onboarding processes. Our lawyers can help – contact office@arws.cz.

New obligations in practice: from technical setup to reporting content

The promise of simplification breaks down when you look at the scope of newly required data. Be prepared to report information you may not have systematically tracked so far:

• Agreements on work activity (DPČ) with remuneration below the threshold for insurance participation.
• Detailed statistical data for the Czech Statistical Office (ČSÚ), such as the highest level of education achieved by each employee.
• A detailed breakdown of all income items, including non-taxable items, enabling the Financial Administration to assess their tax treatment independently.

Implementing JMHZ also requires thorough technical and data preparation. Paper submissions will end and all communication will be electronic only, via one of the following methods:

• XML data message (via data box).
• Direct integration via API interface (VREP/APEP).
• Manual entry in the ČSSZ ePortal (suitable only for companies with very few employees).

A fundamental novelty is the introduction of two unique identifiers that your systems must support and correctly assign:

• Personal Identification Number (OIČ): A unique code for each employee used across state institutions.
• Employment relationship identifier: A unique code for each separate employment relationship (including DPP and DPČ), enabling precise tracking of concurrent engagements.

Important: health insurance funds are outside the system

One of the biggest pitfalls is that obligations towards health insurance funds remain unchanged. Even after JMHZ is launched, you will still have to submit separate reports and statements to each health insurance fund. This means running a dual system, which increases administrative workload and the risk of mistakes.

Employee registration: the biggest change and the highest risk

The most significant and highest-risk change introduced by JMHZ is the abolition of the current 8-day deadline for registering an employee and the introduction of mandatory registration before the start of work. This requires a full review of your onboarding processes. The existing “Notice of commencement of employment” (ONZ) will be discontinued and replaced with a much stricter process.

This obligation applies to all workers without exception, including those engaged under agreements on work performed outside employment (DPP) and agreements on work activity (DPČ), regardless of their income level or participation in sickness insurance.

Rules for foreign nationals (effective from 1 April 2026)

The strictest regime applies to employees without Czech citizenship. You must complete their full registration with all required data no later than before they start working. For foreign nationals, simplified partial pre-registration is not available. This change directly follows the tightened Employment Act rules from October 2025, which introduced the concept of undeclared work with penalties up to CZK 3,000,000.

Rules for Czech citizens (effective from 1 July 2026)

For Czech citizens, registration is also required before starting work. However, the law allows a two-step procedure: partial registration before the start date, and completion of remaining data within 8 days after starting work. If an employee who was already registered ultimately does not start, you must cancel the registration within 8 days.

Our experts on this topic:

Mgr. Jakub Oliva, LL.M., MSc.

associate, partner

• oliva@arws.cz

JUDr. Barbora Kořenářová

associate

• korenarova@arws.cz

FAQ – Legal tips on employee registration

• Does the obligation to register in advance also apply to DPP workers with income up to CZK 10,000?
  Yes. The new system does not distinguish between contract types or income thresholds. You must register absolutely all workers before they start.
• How does registration differ for an EU citizen versus a third-country national?
  For JMHZ purposes, there is no distinction. The term “foreign national” includes all persons without Czech citizenship. From 1 April 2026, the stricter regime of full registration before starting work applies to all. Our lawyers can assist – contact office@arws.cz.

How to avoid potentially crippling fines

The sanction model under JMHZ is strict. Late or incorrect reporting can lead to fines of up to CZK 5,000 for each individual employee affected by the breach.

A simple error in a batch file at a company with 500 employees can therefore result in a fine of CZK 2.5 million. The submission deadline is fixed, with no individual extensions or waivers. If you fail to register yourself as an employer or fail to register an employee on time, a fine of up to CZK 100,000 may apply. If a foreign worker starts work before being properly registered, the State Labour Inspection Office may impose a fine of up to CZK 3,000,000.

If ČSSZ finds an error in your report, it will request correction. You have 8 days from delivery of the request to remedy the issue. The system allows corrective submissions up to 10 years retroactively.

The best defence against penalties is prevention. ARROWS lawyers specialise in preparing documentation that protects you against fines and inspections. We provide comprehensive legal support from document reviews to representation before administrative authorities. Contact office@arws.cz to receive tailored legal support.

How to prepare for JMHZ and what you can do right now

Underestimating preparation is risky. We recommend starting immediately and focusing on four key areas:

1. Perform a data audit: Check whether your systems contain all newly required data, such as employees’ highest educational attainment.

2. Communicate with your payroll software provider: Confirm your payroll system will be ready in time and will support submission via API integration.

3. Redesign HR processes: Adjust recruitment and onboarding workflows to comply with registration before work begins (effective from 1 July 2026).

4. Train your people: Make sure payroll and HR staff understand the new rules and risks.

For our clients, including those with cross-border operations, we provide end-to-end preparation for JMHZ. Through our ARROWS International network, we handle employment matters daily with an international element and can implement processes even for multinational groups. We deliver professional training, prepare internal policies, and review existing documentation. Contact office@arws.cz for tailored legal support.

FAQ – The most common legal questions about JMHZ

1. What happens if I make a mistake in the report?
ČSSZ will request a corrective submission. You have 8 days from delivery of the request to respond. If you fix the issue quickly, ČSSZ may refrain from initiating penalty proceedings. P

2. Does JMHZ also apply to agreements on work performed outside employment (DPP) and agreements on work activity (DPČ)?
Yes, in full scope. You will have to report also those relationships that do not create insurance participation, for example DPČ with remuneration below CZK 4,500.

3. How should I interpret the term “immediately before the start of performing work”?
Unfortunately, the law does not define this term in detail, which creates legal uncertainty. We recommend defining it in an internal policy to ensure your procedure is defensible.

4. What should I do if a registered employee ultimately does not start work?
If you have already registered the employee, you must submit a cancellation of that registration. The law sets an 8-day deadline from the date on which the employee was supposed to start.

5. Will the Pension Insurance Record Sheets (ELDP) be handled through JMHZ?
Yes. The annual ELDP submission obligation will be abolished. ČSSZ will compile the necessary information based on data from twelve monthly reports.

6. What will happen to the annual payroll tax reconciliation?
Based on JMHZ data, the annual reconciliation is expected to be abolished, first for the year 2027. For employees, this should result in a benefit in the form of a pre-filled tax return.

7. How will JMHZ affect the employment of foreign nationals?
Foreign nationals are subject to stricter rules. Their full registration must be completed no later than before they start work, effective already from 1 April 2026. A simplified two-step registration is not available.

8. What if my payroll software provider is not ready for the change?
This is one of the biggest operational risks. It is crucial to contractually address the provider’s liability. We recommend reviewing your IT contracts. Our team can help – contact office@arws.cz.

Disclaimer: The information in this article is of a general informational nature only and is intended as a basic orientation in the topic. Although we aim for maximum accuracy, legal regulations and their interpretation evolve over time. To verify the current wording of the rules and their application to your specific situation, it is necessary to contact ARROWS law firm directly (office@arws.cz). We accept no liability for any damages or complications resulting from independent use of this information without prior individual legal consultation and professional assessment. Each case requires a tailored solution, so do not hesitate to reach out.