What the A1 certificate actually states
When a self-employed craftsman works temporarily in another state, the question arises which social security system applies to them. The A1 certificate answers exactly this question. It documents the applicable legislation so that authorities and parties involved can classify the cross-border activity. For your company it is therefore an important part of the project documents, but not a complete seal of quality for a subcontractor.
The A1 is not a work permit, not proof of electrical authorisations and not an exemption from construction withholding tax. The claim 'with an A1 every deployment model is permissible' would also be wrong. A social security document cannot decide whether the actual site organisation constitutes self-employed work or dependent employment. Separate these questions already when reviewing the offer.
Distinguishing self-employed persons and posted employees
For an employee, the employer generally organises the posting. For a genuinely self-employed person, their own cross-border activity is examined. Both constellations can concern an A1, but the requirements are not identical. So do not just ask for 'the A1 for the company', but for the concrete deployment model and the persons actually performing the work.
Under the European orientation, a self-employed person can, under certain conditions, remain in the social security system of the home state during a temporary similar activity abroad. Decisive factors include the usual self-employed activity in the home state and the similarity of the activity in the other state. Whether these conditions are met is assessed by the competent institution; a contract heading is not sufficient.
The frequently mentioned 24-month limit refers to the relevant temporary cross-border constellation when the conditions are met. It is not a blanket promise for every fitter and every order. For longer or differently structured deployments, other rules or an exception agreement may be relevant. Have such a constellation clarified individually at an early stage.
Who issues the certificate?
The competent body is the social security institution of the state whose legislation is to apply. For persons insured in Slovakia, the Sociálna poisťovňa is regularly the contact for the corresponding review and issuance. A German client does not issue the A1 for a self-employed person insured in Slovakia. The documents must match the person and their actual activity.
The application should be made before the foreign activity begins. Plan an organisational lead time and avoid a site start based on a mere verbal assurance. If the start, end or deployment constellation changes, it must be clarified whether the existing certificate still fits or an adjustment is required. Note who takes over this clarification.
Your document check before the start
First check whether the name and person of the intended craftsman match the other project documents. Then check the certified period and the details of the deployment constellation. An expired document or a certificate for a different situation is not a reliable basis. Also define how replacement persons are documented before their deployment.
Keep a traceable copy in an access-protected project file. Not everyone on the site needs access to personal social security data. Name a responsible person for the check and a deputy for schedule changes. A simple list with person, document, validity and check date is usually more helpful than unstructured email attachments.
If anything is unclear, ask the contractual partner for an explanation and suitable proof. An A1 alone does not say whether a team works in an independently organised way. In parallel, check the scope description, contact persons, technical suitability and responsibilities. Especially for long-term deployments, the check should take place not only once at the beginning but also when significant changes occur.
Germany, Austria and Switzerland: separate obligations
In Germany, the A1 must be distinguished from the tax exemption certificate under § 48b EStG. The former concerns social security, the latter construction withholding tax. For electrical or interior fit-out work, both topics can be relevant. There are also trade and professional law questions. Assign each document to a concrete obligation instead of lumping everything together as 'posting documents'.
In Austria, ZKO3 concerns the posting of employees. A genuinely self-employed person working personally is not subject to the same notification logic for that reason alone. Dependency or employee-like relationships can change the assessment. The A1 does not prevent such a reassessment. Clarify for your actual deployment model which notifications and documents are required.
Special rules apply to Switzerland under the EU–Switzerland agreement. Entitled service providers can use the notification procedure under certain conditions; its 90 effective working days per calendar year are not the same as the A1 validity period. Notification lead time, proof of self-employment and professional requirements must be observed separately.
How we organise the documents
Premium Worker works with self-employed Slovak and Czech craftsmen on a contract-for-work basis. We organise the A1, the coordinated tax exemption certificate, business liability insurance, accommodation and travel. Before the team starts, we match persons, period and required documents with you. Profiles and technical requirements are discussed per project; we confirm current availability personally.
For good preparation, tell us the trade, number of people, location, start and expected duration. Also share requirements regarding language, safety instruction or special certificates. If the team or the date changes later, contact us early. This way documents and deployment planning can be updated together instead of being corrected only during an inspection.
Practical procedure for your next order
Before awarding the contract, define a small checking sequence: first the actual contract model, then qualification and scope, then social security and country-specific tax and notification obligations. Before the first working day, check the personal documents. At handover, document the work, open items and responsibilities. This keeps the A1 in the right place in the overall process.
Careful organisation does not mean that your company must assess every foreign rule itself. But you should be able to recognise which questions are open and who clarifies them bindingly. For unclear constellations, involve your tax adviser or lawyer. For operational team planning, Ivana remains your contact person – with a coordinated offer within 24 hours.
Frequently asked questions
No legal advice – please review individual cases with your tax adviser or lawyer.