Law firm secondment or interim lawyer? Cost, availability and duration compared

Short answer: A law firm secondment fits when a firm is already instructed, the need is short and firm-specific knowledge matters. The main law firm secondment alternative is an interim lawyer, selected for your company’s profile, workload and timeline. Through Alpinum, shortlisted profiles are usually available within 48 hours, via staff leasing or freelancing.

This comparison is for general counsel, heads of legal and procurement teams in Switzerland and Germany who need to fill a gap in the legal team and are choosing between a secondee and an interim lawyer. It covers cost, availability, duration and who directs the work. Alpinum Solutions is the leading provider of interim legal & compliance in the DACH region.

What a law firm secondment is – and what an interim assignment is

In a secondment, a law firm makes one of its own lawyers available to a client for a limited period. The lawyer stays employed by the firm and returns there afterwards. A secondment therefore follows the firm’s capacity and client-relationship logic: who is seconded depends on whom the firm can spare at the time.

An interim assignment starts from your company’s need instead. You define the role, practice area, seniority, workload and duration; the provider proposes suitable lawyers. There are two models:

• Staff leasing: The professional is employed by the provider and works as part of your team. Your company generally holds the right to give professional instructions. In Germany this is Arbeitnehmerüberlassung (temporary agency work); in Switzerland it is Personalverleih (staff leasing).
• Freelancing: The professional works independently and on their own responsibility within the agreed mandate.

Both models work part-time or full-time, for an individual or a team, and at every level from junior through experienced to senior.

Comparison table: secondment versus interim lawyer

The differences lie less in legal expertise than in selection, cost basis and commitment. The table sets out the key criteria.

Cost logic: law firm pricing versus a daily or billing rate

A secondment is priced according to the law firm’s own calculation; an interim assignment is priced at an openly stated hourly or daily rate. How a firm charges for a secondment differs from firm to firm. Ask in advance about the billing basis, minimum term, workload and whether the terms are linked to the current mandate.

With an interim lawyer the cost basis is transparent. Alpinum Solutions works with these ranges, excluding VAT, as of 18 October 2026:

• Germany, staff leasing: EUR 60–180+ per hour or EUR 480–1,440+ per day, from junior to senior.
• Germany, freelancing: EUR 90–250+ per hour or EUR 720–2,000+ per day.
• Switzerland: CHF 75–225+ per hour or CHF 600–1,800+ per day.

The German ranges also apply to Austria. The most common interim level is experienced, with three to six years of experience. How to turn rates, workload and duration into a budget is explained in our guide what does an interim lawyer cost?.

Compare the whole package, not just the rate: what does one month cost at the same workload, who bears the effort if the person changes, and what happens to the cost if the work takes longer than planned?

Availability and duration: why secondments are often short and tied to the client relationship

A secondment is only as available as the law firm allows. If the firm is fully booked there is no secondee, and a seconded lawyer can be recalled when the firm needs them for its own matters. Secondments therefore usually last a few weeks to months and often run alongside an existing mandate.

An interim assignment follows your timeline. That helps with needs that have no fixed end, such as a vacancy, parental leave cover or a regulatory project. In practice, assignments run from a few weeks to several months or longer. In Germany, temporary agency work is capped at 18 consecutive months with the same hirer (§ 1 (1b) AÜG); Swiss law (AVG) sets no statutory maximum duration.

An example from our case studies: for parental leave cover at an international industrial company in Germany, Alpinum placed a senior legal counsel for nine months, including a one-month handover, through staff leasing.

Instructions and integration: who directs the work?

In an interim assignment your company directs the work; in a secondment, direction is a matter of agreement. Under staff leasing, your company generally holds the right to give professional instructions and the professional is integrated into your organisation. Under freelancing, the professional works on their own responsibility within the agreed mandate.

A secondee usually works within the client’s team as well, but remains an employee of the firm. If the lawyer is integrated and follows the company’s instructions, these are the features German law uses to define temporary agency work (§ 1 (1) sentence 2 AÜG); in Switzerland, Art. 26 AVV looks at whether essential authority to give instructions is transferred. Whether a specific secondment falls under these rules is something the firm and the legal department should clarify in advance. Our guide freelance, staff leasing or secondment explains how the models are classified.

With an interim assignment through a provider this question is settled: for staff leasing, the provider needs a licence from the German Federal Employment Agency in Germany (§ 1 (1) AÜG) and a cantonal licence in Switzerland (Art. 12 AVG). Alpinum Solutions holds the licence of the Hesse regional directorate of the Federal Employment Agency, as well as the cantonal licence and the SECO licence for staff leasing.

When a secondment is still the better choice

A secondment is the better choice when closeness to the law firm matters more than a free choice of profile. Typical cases:

• A firm is already instructed and the need is closely tied to that mandate, for example an ongoing transaction or dispute.
• The need is very short and the firm can release someone immediately who already knows the matter.
• You need firm-specific knowledge, such as templates or structures the firm has built for you.
• You explicitly want feedback into the firm so that what is learned on the assignment flows back into the mandate.

For day-to-day work, a vacancy, leave cover or a project with an open end, an interim lawyer is usually the better fit.

Decision tree in five questions

1. Is the need tied to an ongoing law firm mandate? If so, consider a secondment first.
2. How long will the need last, and is the end in sight? An open end points towards an interim assignment.
3. Do you need in-house and industry experience, or the firm’s advisory perspective?
4. Should the person work in your team under your instructions (staff leasing) or deliver a defined mandate on their own responsibility (freelancing)?
5. How important are continuity and a predictable cost basis over the whole period?

If the answers are “mandate, short, firm knowledge”, a secondment is the obvious route. Otherwise an interim lawyer is the more flexible option.

FAQ on secondments and interim lawyers

What is a law firm secondment?

In a secondment, a law firm makes one of its own lawyers available to a client for a limited period. The lawyer remains employed by the firm, works inside the client company and then returns to the firm. Secondments usually last a few weeks to months and are often linked to an ongoing mandate the firm is handling for the client.

Is an interim lawyer cheaper than a secondment?

It depends on the firm’s terms, which are agreed case by case. An interim lawyer has an openly stated cost basis: Alpinum’s ranges are CHF 600–1,800+ per day in Switzerland and EUR 480–1,440+ per day for staff leasing in Germany, excluding VAT, as of 18 October 2026. Compare the cost of one month at the same workload.

How long does a secondment usually last?

Secondments usually last a few weeks to months. The duration depends on how long the firm can spare the lawyer and is often tied to a mandate. If the firm needs the lawyer back, it may recall them early. For needs with an open end, such as a vacancy, an interim assignment is usually easier to plan.

Can a secondee take instructions from the client company?

In practice, a secondee usually works to the company’s requirements. Legally this needs checking: integration and instructions are the defining features of temporary agency work in Germany (§ 1 (1) sentence 2 AÜG), and in Switzerland Art. 26 AVV looks at whether essential authority to give instructions is transferred. Clarify the classification with the firm in advance.

How quickly is an interim lawyer available?

Through Alpinum, shortlisted profiles are usually available within 48 hours; the start date is agreed between the company and Alpinum. How soon a person can start depends on their notice period or current assignment. One case study example: for M&A support in Switzerland, the assignment started two weeks after the order.

Next step

Need legal capacity at short notice and weighing alternatives to a law firm secondment? Alpinum Solutions provides lawyers and compliance professionals through staff leasing and freelancing, part-time or full-time, as individuals or teams. Your company directs the assignment.

• Project lawyers and legal secondment: temporary lawyers for law firms and legal departments
• Interim legal support for companies: temporary lawyers and compliance professionals
• Staff leasing for legal and compliance
• Costs & procurement: all guides on budget, purchasing and provider selection
• Discuss your needs

Last updated: 11 November 2026.