JMHZ: What is it, and when (and how) will it start to affect us?

What is JMHZ?

The Unified Monthly Employer Report (JMHZ) is a new way for employers to submit data to the state regarding employees, employment relationships, and social security/tax contributions. JMHZ replaces a range of existing forms and consolidates filings for multiple authorities into a single electronic report. Data will be shared among authorized "data users" (Czech Social Security Administration - ČSSZ, health insurance companies, Financial Administration, etc.).

Main goals: simplifying administration, one filing instead of many, and a unified deadline and format (XML/web). Paper submissions will no longer be permitted.

When does it take effect?

Due to the technical preparation required for the full launch, the rollout is somewhat specific.

January 1, 2026 – The JMHZ Act and implementing regulations come into force. For January–March 2026, the Premium Amount Overview (PVPOJ) is not submitted, though premiums must still be paid as usual.
April 1, 2026 – Launch of regular JMHZ: the report for April 2026 must be filed between May 1–20, 2026. Simultaneously, employers must retroactively submit JMHZ reports for January–March 2026 between April 1 and June 30, 2026.
July 1, 2026 – Mandatory pre-registration of employees before they start work (partial record-keeping). For foreign nationals, pre-registration does not apply; full reporting is required before they start.

Who does JMHZ affect?

All employers, including those using work agreements (DPP and DPČ). The definition of "employees" for JMHZ is broader than the current scope used by the ČSSZ.

What does JMHZ replace?

JMHZ will gradually replace multiple forms across various agendas (e.g., the monthly PVPOJ for ČSSZ, selected registration and statistical reports). A detailed list of requirements and data structures is set by government decrees and implementing regulations.

New Identifiers

OIČ – Personal Identification Number of the employee, assigned once and permanent.
IZ – Employment Identifier, linking a specific employee to a specific employment relationship.
VS – Employer/Payroll Office Variable Symbol for JMHZ. This will be unified and permanent; employers currently registered only with the Financial Administration will receive it from the ČSSZ.

The ČSSZ will bulk-deliver OIČ and IZ codes for workers who were registered for at least one day between January 1 and March 31, 2026, so they do not need to be reported again.

Employer and Employee Registration

Employer Registration

Until March 31, 2026, existing registrations with the Social Security Office (OSSZ) and Financial Administration remain in effect.
From April 1, 2026, employers register once in the JMHZ employer registry. New employers must register within 8 days of their first employee's start date (and from July 1, 2026, in advance—see pre-registration).
Employers "transferred" automatically by the ČSSZ from Financial Administration registers must provide additional details by April 30, 2026.

Employee Registration

Until March 31, 2026, the current 8-day "Notice of Entry" rule applies.
From April 1, 2026, employees are registered in the JMHZ registry; the 8-day deadline remains.
From July 1, 2026: Mandatory pre-registration before starting work; remaining data must be completed within 8 days of entry. Foreign nationals require full reporting before starting.

Monthly Reporting: What, When, and How

Deadline: Always between the 1st and 20th day of the following month. For January–March 2026, JMHZ is submitted retroactively between April 1 and June 30, 2026 (each month separately). For April 2026, the standard deadline of the 1st–20th of the following month applies.

Filing Structure

Summary Section – Employer details and tax reconciliation summary.
Insurance Section – Total amount of social security premiums.
Individualized Sections – Data specific to individual employment relationships.

Submission Methods

ČSSZ ePortal web interface.
XML data message via ČSSZ Data Box.
Automated APEP/VREP interface.

The system will flag formal/technical errors and allow for corrective or subsequent reports, including cancellations. The law does not allow for individual deadline extensions.

What to do now: Checklist

Verify your VS (Variable Symbol) assignment for JMHZ. If you were previously only with the Financial Administration, the ČSSZ will deliver it.
Verify that your payroll software is ready for JMHZ data structures (XML).
Map out all employment relationships, including work agreements (DPP/DPČ). Clarify internal processes for pre-registration starting July 1, 2026.
Prepare for retroactive filings for Q1/2026 between April 1 and June 30, 2026.
Set up processes for reporting changes within 8 days and for regular filings between the 1st and 20th of each month.

Frequently Asked Questions

Do I need to send PVPOJ in Q1/2026?

No. PVPOJ is not sent in Q1/2026. However, you must pay premiums as usual. Compliance will be checked after the retroactive JMHZ for January–March 2026 is filed.

What if an employee does not start on July 1, 2026?

After the expected start date, there is an 8-day window to de-register or cancel the record.

Will authorities have access to all my data?

No. Each "data user" only accesses the scope of data defined by their specific agenda and implementing regulations.

Quick Summary

January 1, 2026 – JMHZ and regulations take effect; Q1 PVPOJ is not filed.
April 1 – June 30, 2026 – Retroactive filing for Jan–Mar 2026; monthly reporting for April 2026 begins.
July 1, 2026 – Mandatory pre-registration before start (full reporting for foreign nationals).

Sources:

Primary Legislation
Act No. 323/2025 Coll., on the Unified Monthly Employer Report
Act No. 360/2025 Coll., Amending Act to JMHZ
Government Decree No. 417/2025 Coll., implementing the JMHZ Act
Explanatory Memorandum to Decree No. 417/2025 Coll.

Official MPSV Information
Unified Monthly Employer Report – Official MPSV Portal
MPSV Press Release: New JMHZ system to simplify employer administration

Practical Overviews and Commentaries
POHODA.cz: Important Deadlines for JMHZ
Podnikatel.cz: JMHZ to launch new employee registries next year
Podnikatel.cz: Employer and Employee Registration – Duty Overview
Money.cz: Summary of changes and JMHZ impact on payroll systems