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How to set up an in-house legal department

Written by Andrew Mellett | 26/06/2026 1:33:51 AM

Bringing legal in-house is a turning point for a growing business. Done well, it gives faster, more commercial legal support and brings rising external costs under control.

When does a business need an in-house legal department?

The trigger is usually a combination of cost and volume. When external legal fees become a significant line item, when the amount or complexity of legal work outpaces what can sensibly be managed through law firms, and when the business needs legal advice that is faster and more embedded in its day-to-day decisions, it is time to build an in-house capability.

How do you set up an in-house legal department?

Setting up a function is less about hiring quickly and more about building the right foundations. Five steps matter most.

Define the scope and mandate

Be clear about what the function will and will not do. Define the types of work it will handle, how it will interact with the business, and where external firms still fit. A clear mandate prevents the team being overwhelmed from day one.

Decide the structure and first hires

Most functions start with a single lawyer or small team covering everything, then specialise as they grow. Hire first for the work that is highest volume or highest risk for your business, and build from there.

Set up processes for intake and prioritisation

Decide how the business will request legal support and how those requests will be triaged. Structured matter management from the outset stops the team being driven purely by whoever shouts loudest.

Choose the right technology

Technology is how a small team supports a large business. Contract automation, a central repository, and Plexus AI let a lean function handle far more work than its headcount would suggest, and should be set up early rather than bolted on later.

Define how you measure success

Decide from the start how you will show the function is working, using metrics such as turnaround times, volumes and cost savings. Our guide to the legal KPIs that matter to the C-suite is a useful starting point.

What does a typical in-house legal department structure look like?

In the early stages the structure is flat: one lawyer or a small team handling everything from contracts to disputes. As the function matures it specialises, commonly into commercial and contracts, disputes and litigation, compliance and regulatory, and employment, with a general counsel leading the whole and owning the relationship with the executive and board.

In-house legal vs external law firms: what to keep in-house?

The aim is not to bring everything in-house. High-volume, business-as-usual and commercially embedded work belongs in-house, where speed and business context add the most value. Specialist, high-stakes or one-off surge work, such as major litigation or complex transactions, is usually better handled by external firms. A good in-house function manages that balance deliberately.

How Plexus helps new legal functions do more with less

A new legal function rarely has the headcount it would like, which makes technology decisive. Plexus lets a small team automate contracts and routine work, keep everything visible in one place, and scale support across the business without adding lawyers. See how it fits together on the platform overview.