A1 certificate in the Czech Republic: step by step
An in-house counsel at a Czech employer is asked to send two engineers to a client site in Austria for eleven weeks. Payroll needs assurance that Czech social security keeps covering the assignment rather than Austrian. The certificate that gives that assurance is not automatic, and the office that issues it works to its own calendar, not to the project's start date. The same question follows every posting, regardless of how routine it looks on the schedule.
An A1 certificate confirms which state's social security system covers an employee posted temporarily to another EU or EEA state, and it is filed with the Czech Social Security Administration before the posting starts. Czech administrative procedure and EU coordination rules govern it, and the form must describe one specific posting, not the whole assignment.
This page sets out who files the application and where, the deadline that runs before the posting begins, and what the supporting file must contain before the office will act.
What triggers the need for an A1 certificate?
An A1 certificate becomes necessary whenever a Czech employer sends an employee to work temporarily in another EU or EEA state or Switzerland while keeping the employment relationship in the Czech Republic. The same applies to a self-employed person carrying out temporary activity abroad, and to a person working simultaneously in two or more member states.
The trigger is the posting of workers itself, not the industry or the contract value. A short business trip without actual work performed does not require the certificate; a genuine assignment, however brief, does. A separate question, addressed in the note on transfer of undertaking, arises when the posting follows a change of employer rather than a temporary assignment, and that situation runs on a different track entirely. A German-owned logistics operator discovered its Czech drivers had been working in Poland without an A1 record for several weeks after a schedule change went unreported (spring 2025); the gap surfaced only during a routine audit. Employers who let the posting start before the certificate is filed cannot simply backdate the contribution record afterwards. The host state's inspectorate can treat the unrecorded period as an uninsured one, and that gap does not close on request once the assignment has run its course.
The certificate travels with the worker, not with the project - a new assignment after the first one ends needs its own filing.
When does the posting rule actually apply?
The A1 procedure applies where the posting is genuinely temporary, where the employer maintains a substantial activity in the Czech Republic, and where the posted employee remains under a Czech employment contract for the duration. Each of the three conditions is checked separately, and all three have to hold.
A posting is temporary when it is planned for a defined period, usually up to twenty-four months, and is not a rolling replacement of a worker previously posted to the same position. The employer's substantial activity in the Czech Republic is assessed against turnover, staff and contracts actually carried out here, not against the registered address alone, and the first step is establishing which employer's registered seat governs the application. Where the employee works for two or more employers established in different states, a distinct set of rules applies. Confirming that the signatory on the employer's side is still an acting statutory representative is worth doing before submission - see the preview of a management record for what that check covers.
Getting the file wrong at this stage usually surfaces only once the host state's inspectorate asks for the certificate on site, and by then the posting is already running without cover. LISTINA produces a factual report on the posting's structure and the documents it will need before filing, delivered in five to eight working days; write to info@listinafirm.com. Representation before the Czech Social Security Administration, if it becomes necessary, is provided by a collaborating advocate.
What is the route, and what is the deadline for filing?
The application is filed with the Czech Social Security Administration before the posting begins, using the employer's registered forms and the employee's specific work schedule abroad. There is no fixed statutory number of days by which the application must arrive, but Czech practice treats a delay after the posting has already started as a defect in the filing, not a formality.
- The employer identifies the posting: destination state, host employer if there is one, and the exact dates of work abroad
- The Czech Social Security Administration's district office of the employer's registered seat receives the application, normally before departure
- The office reviews the employment relationship and the substantial-activity test
- The certificate, once issued, is handed to the employee for the duration of the posting
- Any change to the dates or the destination is reported as an amendment, not a new filing
An Austrian construction group found that a Czech subcontractor's certificate covered a different work site than the one actually used, a mismatch traced only after a labour inspection in the host state (autumn 2025). Sending personal data connected with the posting to the host state's authority raises its own question, covered separately in the note on employee liability for data sent abroad. A posting that starts before the certificate is confirmed risks the host state opening its own social security assessment for the period already worked, and once that assessment is opened, withdrawing it is not within the employer's control.
The office decides on the file as submitted - a certificate issued on an incomplete description of the posting is often reopened once the mismatch surfaces on site.
What the file must contain
The file has to describe one posting: the employer, the employee, the host state, the exact dates, and the basis on which the employee remains covered by Czech social security. Missing any one element is the most common reason an application is returned for correction rather than decided.
Where the posting coincides with a change in the underlying employment contract - a revised notice period, for instance, or a temporary change of position - the office asks for the contract itself, not a summary of it. The description of duties abroad has to match what the employee is actually contracted to do in the Czech Republic; a mismatch between the two is read as evidence that the posting is not what it is described to be.
- The employment contract, including any addendum covering the posting itself
- A description of the work to be carried out abroad and its expected end date
- Confirmation of the employer's activity carried out in the Czech Republic
- The host state, the site or sites of work, and the host employer if there is one
- Proof that the employee was insured in the Czech Republic before the posting began
A file returned for correction after the posting has already started leaves the employer without cover for the days already worked, and that period is rarely fixed retroactively without friction. LISTINA prepares the factual summary of the posting and the supporting file before it goes to the office, delivered in five to eight working days; write to info@listinafirm.com. Representation before the Czech Social Security Administration, if it becomes necessary, is provided by a collaborating advocate.
Act, wait, or stop: the decision point
Once the posting's dates and the employee's status are settled, filing without delay is the position that avoids a coverage gap. Where the underlying employment relationship itself is unsettled, the filing should wait until that question is resolved.
Severance negotiations, a running notice period or an open works council consultation belong to a separate employment track and are not decided within the A1 procedure. They do, however, change what the file can honestly describe, and filing before they are resolved risks a certificate that no longer matches the underlying relationship once it is issued.
What cannot be established from the file alone: whether the host state's authority will accept the certificate without further inquiry, and whether a parallel inspection has already started in the host state before the Czech application was filed. Both depend on records the Czech Social Security Administration does not hold.
- Posting dates and duties settled, no pending contract change – file before departure – employer – before the posting starts
- Posting dates set, employment terms still under negotiation – wait for the contract to close – employer and employee – before filing, not before departure
- Certificate already issued, destination or dates change – file an amendment – employer – as soon as the change is known
- Host state opens its own assessment for an unrecorded period – respond through the Czech office, not directly – employer – immediately
A certificate filed only after the host state's inspectorate has already asked for it rarely closes the matter cleanly. The inspectorate keeps its own record of the inquiry, and a late filing does not erase the period during which the posting ran unrecorded.
The certificate is a record of coverage, not a permit to work - the two are decided by different authorities on different questions.
Frequently asked questions
Where is A1 certificate filed?
The application goes to the Czech Social Security Administration, at the district office covering the employer's registered seat, before the posting begins. A self-employed applicant files at the office covering the place of business rather than a client site abroad.
How long does the court take?
No court decides this matter - the certificate is issued by the Czech Social Security Administration through an administrative procedure, not by a court. Processing normally runs from a few weeks to a couple of months depending on the office's caseload and whether the file is complete on first submission.
Can the other side object?
There is no opposing party in the ordinary sense, but the host state's authority can challenge the certificate's accuracy after it is issued, typically once an inspection finds the posting does not match the description filed. That challenge is resolved between the two states' authorities, not by the employer directly.
What follows the decision?
Once issued, the certificate is given to the employee to carry for the duration of the posting and produced if the host state's inspectorate asks for it. Any change to the dates or the destination has to be reported as an amendment before it takes effect.
LISTINA produces factual reports from documents and public registers. It does not provide legal advice and does not represent parties. Where a matter requires representation before a Czech court or authority, it is handled by a collaborating advocate.
An A1 filing that starts late or incomplete is difficult to fix once the posting is already running. LISTINA delivers a factual report on the posting structure and the supporting file, prepared in five to eight working days; write to info@listinafirm.com. Representation before the Czech Social Security Administration, if it becomes necessary, is provided by a collaborating advocate.