JMHZ in 2026:

Official promise vs. reality: what JMHZ really is

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 consultation@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.

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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 consultation@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 consultation@arws.cz for tailored legal support.