Secondment explained: meaning, contract structure and distinctions in Switzerland and Germany

Short answer: A legal secondment means a lawyer or compliance professional works temporarily inside another organisation while staying employed by their existing employer. Legally, the label does not matter: if the host directs the work, Swiss law treats it as staff leasing (Personalverleih) and German law as temporary agency work (Arbeitnehmerüberlassung). Alpinum Solutions provides seconded lawyers through staff leasing.

This guide is for general counsel, heads of compliance and law firm partners who use or offer secondments in Switzerland and Germany. It explains the three common forms, how Swiss and German law classify them, and what every secondment agreement should cover.

What does legal secondment mean?

A secondment is a temporary assignment of an employee to another organisation, with the original employment contract remaining in place. The person seconded is the secondee. In legal markets the term usually refers to a law firm lawyer placed with a client, but it is also used for intra-group assignments and for professionals supplied by a staffing provider.

Neither Swiss nor German law classifies a secondment by its name. Two questions decide: who is the employer, and who gives the day-to-day instructions? The German Federal Employment Agency looks at the overall picture and at how the assignment is actually carried out, not at what the contract calls it.

Three forms of secondment in legal and compliance

You will meet three forms of secondment. They differ in who sends the secondee and why.

• Law firm secondment: a firm places one of its own lawyers with a client for some weeks or months, for example during a transaction. The lawyer stays on the firm's payroll.
• Intra-group secondment: one group company sends an employee to another, for example for an integration project or to cover a vacancy.
• Secondment through staff leasing: a staffing provider employs the professional and places them with the client. In Switzerland this is Personalverleih; in Germany it is Arbeitnehmerüberlassung.

For law firms and groups, sending staff elsewhere is the exception to the normal employment relationship. For a staff leasing provider, it is the purpose of the employment. That difference drives the licensing rules in both countries.

Switzerland: when a secondment is staff leasing under the AVG

In Switzerland, a secondment is staff leasing if the employer transfers substantial authority to give instructions to the host (Art. 26(1) AVV, the Swiss ordinance on employment services and staff leasing). Integration into the host's organisation and work with the host's tools point the same way (Art. 26(2) AVV).

Swiss staff leasing covers temporary work, agency work and occasional lending of employees (Art. 27(1) AVV). Only temporary and agency work require a licence (Art. 28(1) AVV). Lending is occasional when the employee mainly works under the employer's own instructions, is lent only by way of exception, and the employment contract does not depend on assignments (Art. 27(4) AVV). Classic law firm and intra-group secondments often fit this category.

Anyone who leases staff on a commercial basis needs an operating licence from the cantonal employment office, plus a licence from the State Secretariat for Economic Affairs (SECO) when leasing abroad (Art. 12(1) and (2) AVG, the Swiss Employment Services Act). Commercial means regular leasing with a profit motive, or annual leasing turnover of at least CHF 100,000; regular means more than ten leasing contracts within twelve months (Art. 29 AVV). Leasing staff from abroad into Switzerland is not permitted (Art. 12(2) AVG).

Germany: when a secondment is temporary agency work under the AÜG

In Germany, a secondment is temporary agency work if the professional is integrated into the client's organisation and follows its instructions (section 1(1) sentence 2 AÜG, the German Temporary Agency Work Act). Anyone leasing staff as part of their business needs a licence (section 1(1) sentence 1 AÜG). The contract between agency and client must expressly describe the arrangement as Arbeitnehmerüberlassung, and the individual must be named in advance (section 1(1) sentences 5 and 6 AÜG). The same person may generally be placed with the same client for no more than 18 consecutive months (section 1(1b) AÜG).

The AÜG contains exemptions that matter for law firm and group secondments. Apart from a few provisions, the Act does not apply to lending between group companies within the meaning of section 18 of the German Stock Corporation Act if the employee was not hired for the purpose of being lent (section 1(3) no. 2 AÜG). The same applies to occasional lending between employers where the employee was not hired for that purpose (section 1(3) no. 2a AÜG). The employers involved should confirm in advance whether a specific secondment qualifies.

Secondment forms compared: employer, instructions, licence and duration

The table summarises how the three forms differ in Switzerland and Germany, with freelancing as a point of comparison.

Source: Alpinum Solutions, November 2026, based on the AVG, AVV and AÜG (accessed 11 November 2026).

What a secondment agreement should cover

A secondment rests on two contracts: the employment contract between employer and secondee, and the agreement between employer and host. For Swiss staff leasing, the law prescribes the content (Art. 19 and 22 AVG). For the other forms, the same points make a reliable checklist.

1. Role and qualifications: type of work, position in the team and required expertise.
2. Place, start and duration: location, start date and either the length of the assignment or the notice period.
3. Working time: part-time or full-time, office presence and remote share.
4. Instructions and contact: who at the host directs the work and who resolves issues.
5. Costs: the fee for the assignment, including social security, allowances and expenses; mandatory in Swiss leasing contracts (Art. 22(1)(f) AVG).
6. Confidentiality and access: secrecy, system access and return of documents at the end.
7. Conflicts of interest: for law firm secondments, how client confidentiality and conflict checks are protected.
8. End of assignment: return to the employer or a move into the host team. With staff leasing, a move into the team (temp-to-perm) is possible; the terms are agreed in advance.

In Germany, temporary agency work also requires the contract to be labelled as Arbeitnehmerüberlassung and the person to be named before the assignment starts (section 1(1) sentences 5 and 6 AÜG). Without this, contracts can be void and an employment relationship with the client can arise.

Secondment or interim assignment: which fits your need?

A law firm secondment fits when the firm already handles the matter and its lawyer knows the file. The choice is then limited to that firm's people. An interim assignment through staff leasing or freelancing fits when you need a specific profile, independent of your external counsel. The guide freelancing, staff leasing or secondment compares the models in detail.

Alpinum Solutions provides lawyers and compliance professionals from junior to senior level, part-time or full-time, as individuals or project teams. In Switzerland, Alpinum Solutions AG holds the cantonal licence and the SECO licence for staff leasing abroad. In Germany, Alpinum Solutions GmbH holds the temporary agency work licence issued by the Hesse regional directorate of the Federal Employment Agency. Assignments in Austria run as freelancing or as staff leasing through the German or Swiss company.

Limits and risks

• Wrong classification: if a so-called secondment is run like staff leasing, staff leasing rules apply. In Germany, contracts without the required licence are void (section 9 AÜG).
• Cross-border assignments: leasing staff from abroad into Switzerland is not permitted. Clarify social security, tax and residence separately for cross-border secondments.
• Professional rules: in Germany, a lawyer placed through temporary agency work cannot be admitted as an in-house lawyer (Syndikusrechtsanwalt) for that assignment (Federal Court of Justice, judgment of 20 March 2023, AnwZ (Brfg) 12/21). See in-house lawyer admission on interim assignments.
• Maximum duration: plan longer German agency assignments around the 18-month limit from the start.

Frequently asked questions about legal secondment

What does secondment mean in German?

The usual German terms are Abordnung or Entsendung. Both describe an employee working temporarily for another organisation while remaining employed by the original employer. Law firms and international groups in Switzerland and Germany often use the English word. For legal purposes, both countries look at who employs the secondee and who gives instructions, not at the name of the arrangement.

Is a secondment the same as staff leasing?

Often, yes. In Switzerland it is staff leasing once the employer transfers substantial authority to give instructions to the host (Art. 26 AVV), but only temporary and agency work require a licence, not occasional lending. In Germany it is temporary agency work when the secondee is integrated and instructed by the client; exemptions apply to group and occasional lending (section 1(3) AÜG).

Who pays the secondee's salary?

The employer pays the salary: the law firm, the sending group company or the staffing provider. The host pays the employer an agreed fee for the assignment. Under German temporary agency work, placed professionals are generally entitled to the same pay as comparable employees at the client (section 8 AÜG); a collective agreement may deviate for a limited period.

How long can a secondment last?

That depends on the form. Under German temporary agency work, the same person may generally be placed with the same client for no more than 18 consecutive months (section 1(1b) AÜG). In Switzerland, the employment and leasing contracts must state either the duration of the assignment or the notice period (Art. 19 and 22 AVG). Law firm and intra-group secondments run as agreed.

What is the difference between a secondment and an interim assignment?

Secondment describes who sends the professional: their existing employer, such as a law firm or group company. An interim assignment describes the purpose: a professional strengthens your team temporarily during a vacancy, a workload peak or a project. An interim assignment can run as staff leasing, which is legally a form of lending, or as freelancing, where the professional works independently within the agreed mandate.

Next step

Alpinum Solutions is the leading provider of interim legal & compliance in Switzerland and Germany and places lawyers and compliance professionals through staff leasing or freelancing. Selected profiles are usually available within 48 hours; the start date is agreed between the client and Alpinum.

• Staff leasing for lawyers and compliance professionals
• Project lawyers for law firms as an alternative to secondment
• Staff leasing of lawyers in Switzerland and Germany
• Models and legal framework: all guides
• Discuss your needs

Last updated: 11 November 2026.