A subcontractor offers you crews “with their own people from abroad” — quickly available, one price, one contact person. What the offer rarely says: whoever deploys posted workers on their construction site takes on legal obligations that cannot be delegated away. This article sorts out the three terms everything hinges on in practice: posting, the A1 certificate and the notification requirement.
What posting means legally
Posting means that a company based abroad sends its own employees to Germany temporarily to fulfil a contract here. The employment contract stays with the foreign employer, and social insurance continues — under certain conditions — in the country of origin. That is one construction. The other is direct employment: the German company hires the international worker itself, with a German employment contract and German social insurance from day one.
Both routes are legal. They merely distribute responsibility and control completely differently: with posting, the German client buys a service and relies on the foreign employer handling pay, social contributions and notifications correctly. With direct employment, the client has all of that in its own hands. How registration works from day one with direct employment is described in our article on social insurance for international employees.
The A1 certificate: small, inconspicuous, decisive
Whether a posted worker may remain insured in the country of origin is decided by the A1 certificate. It is issued by the social insurance institution of the country of origin and confirms that no German social insurance contributions are due for the duration of the assignment in Germany. A posting is limited in time — as a rule to a maximum of 24 months (Source: Regulation (EC) No 883/2004 on the coordination of social security systems).
The order of events matters: the A1 certificate is applied for in the country of origin before the assignment begins — not retrospectively when an inspection is due. It applies per posting and per person; there is no collective document for the whole crew. And it answers only the social insurance question. In labour law, the German minimum working conditions apply alongside it; in residence law, third-country nationals additionally need a title permitting employment in Germany — an A1 does not replace a visa.
For practice on site, one detail counts: the A1 certificate must be available during the assignment and be presentable at an inspection. If it is missing, the suspicion stands that the worker is subject to insurance in Germany — with back payments of contributions and fines as the possible consequence. A client deploying a subcontractor’s crews therefore does well to have the A1 certificates shown before the work begins, not when the customs financial control against illicit work is standing in the yard.
The notification requirement: before the first hand is lifted
Independently of social insurance, a second obligation applies: a foreign employer posting workers to Germany in sectors covered by the German Posted Workers Act — construction is one of them — must register the posting with the customs administration before the work begins. The notification runs digitally through the Minimum Wage Reporting Portal and contains, among other things, the place of assignment, its duration and the personal details of the workers deployed (Source: German Customs / Central Customs Authority, minimum working conditions; Baulohn.com, posting of workers in the construction industry).
Then there is pay: posted workers are entitled to the German minimum working conditions. In the main construction trades in 2026 that concretely means 15.25 euros per hour for labourers and 18.59 euros for skilled workers in the West (Source: Collective agreement on minimum wages in the main construction trades, cited from Baulohn.com, 2026). And in the construction industry, a posting company generally also remains obliged to participate in the SOKA-BAU social fund scheme — the contributions do not simply run along abroad.
Section 14 of the Posted Workers Act: why the liability stays with you
Now for the most uncomfortable part, which never appears in offers. Section 14 of the German Posted Workers Act makes the client of a work or service contract a guarantor: if the subcontractor — or its subcontractor — fails to pay the minimum wage, the worker can claim the net pay directly from the German client. This liability runs down the entire chain of subcontractors and cannot be excluded by contract (Source: German Posted Workers Act, Section 14; Baulohn.com, 2026). The same principle applies to the social fund contributions in the construction industry.
That is the core of the image line above this article: your subcontractor posts the workers — the liability stays with you. The cheap crew price of a provider who cuts corners on pay or fund contributions is therefore not a procurement win, but an open risk on your balance sheet. It can be checked seriously: A1 certificates, the customs notification, a clearance certificate from SOKA-BAU — whoever cannot or will not show these documents has already given you the answer.
Who checks this — and what happens in case of violations
Responsible for enforcement is the customs financial control against illicit work. It inspects construction sites unannounced, checking whether the registered people are actually the ones working, whether A1 certificates are available, and whether the minimum working conditions are being observed. For the client, inspection day is the wrong moment to see the subcontractor’s documents for the first time.
A second trap deserves its own paragraph: the line between a work contract and the hiring-out of workers. A posting requires the subcontractor to deliver its own work under its own direction. As soon as your site management gives the posted people direct instructions, assigns them into your crews and controls their working hours, the construction effectively tips into hiring-out — and that is illegal without a licence, and in the main construction trades for manual workers fundamentally prohibited. What looked like a work contract becomes a legal violation both sides are caught in. The practical rule of thumb: whoever directs other people’s staff like their own should employ them themselves.
Posting or direct employment: the honest trade-off
Posting has its legitimate place: for time-limited trades in which an established foreign team delivers a defined piece of work. Its limits lie where the temporary assignment turns into permanent staffing needs — because the 24 months run out, the people never belong to your company, and every extension of the chain also extends your liability.
Direct employment turns the relationship around. The route takes longer — four to six months for a skilled worker with recognition, two to four via the Western Balkans regulation — but at the end there is your own employee inside the German system: German social insurance, a German employment contract, no A1 construction, no guarantor liability for someone else’s payroll. What the difference between a work permit and a residence permit means in practice is covered in work permit or residence permit; the cost side of the temporary-work alternative is calculated for the restaurant industry here.
The information in this article is for orientation and does not replace legal advice. Binding are the case-by-case statements of the customs administration, the social insurance institutions and SOKA-BAU.
What to check before the next subcontractor agreement
Four points that can be clarified in a quarter of an hour and save months of trouble.
First: Are A1 certificates available for all workers deployed — and do they cover the assignment period?
Second: Has the posting been registered with customs? Have the confirmation of notification shown to you.
Third: Can the subcontractor present a current clearance certificate from SOKA-BAU?
Fourth: Recalculate the hourly rate. A price below minimum wage plus social fund contributions plus margin can only come about in one way — and for that way, in the end, you are the one liable.
And a final point in fairness to the reputable posting companies, which of course exist: whoever presents the four documents without hesitation has nothing to hide — the check ultimately protects them too, because it makes them distinguishable from the cut-price provider who cannot. A subcontractor who takes offence at these questions has told you more than any reference list.
If the need is permanent, the other route is worth a look: your own international employees, directly employed, in around four months from contract. For the record: we deliberately give no success figures from our own placements in this article — what we describe is the legal position, not a result we cannot yet show.
Further reading
- Social insurance for international employees: day one
- Work Permit or Residence Permit: The Difference
- Costs of Temporary Labor in the Restaurant Industry: An Honest Breakdown
Sources
- German Customs / Central Customs Authority: Minimum working conditions. https://www.zoll.de/DE/Fachthemen/Arbeit/Mindestarbeitsbedingungen/mindestarbeitsbedingungen_node.html (accessed 27 August 2026)
- Baulohn.com: Posting of workers in the construction industry — notification requirements, minimum wage and SOKA-BAU. 2026. https://baulohn.com/blog/arbeitnehmerentsendung-bau/ (accessed 27 August 2026)
- German Posted Workers Act (Arbeitnehmer-Entsendegesetz), Section 14 — Liability of the client. Official legal text (Federal Ministry of Justice, gesetze-im-internet.de).
- Regulation (EC) No 883/2004 on the coordination of social security systems (A1 procedure). Official Journal of the European Union.
