We recently sat down with the operations lead at a founder-led services group that keeps launching new companies. Every few months another entity spins up: a new services division, a consulting arm, a construction company, a long-term facility project. Same founder, same core team, different legal entity each time. If that sounds like your world, the questions that follow are worth thinking through before the fifth company shows up.
The instinct is usually to run everything out of one shared setup because the people are the same. That works right up until it doesn't. Separate legal entities often need separate boundaries, and sometimes one of them has to stay genuinely independent for reasons that have nothing to do with convenience.
Separate entities, separate tenants
When each company is its own LLC, the cleanest pattern is usually a separate Microsoft 365 tenant per entity rather than cramming everyone into one. It costs more and it's more to manage, but it keeps identities, data, and billing cleanly attributable to the right company. That matters for accounting, for any future sale or spin-off, and for keeping one company's incident from bleeding into another's.
There's a real trade-off here, and it's worth naming plainly. One tenant is simpler to administer and cheaper. Multiple tenants keep the entities clean but multiply the setup, the licensing lines, and the day-to-day management. The right answer depends on how independent these companies actually need to be, not on which is less work this quarter.
Tenant boundaries are hard to add after the fact. If two entities might ever need to separate cleanly, it's far easier to start them apart than to untangle them later.
When one entity has to stay legally independent
In this case one of the new companies has to sit at arm's length from the parent, with no ownership stake held by the founder. The driver is regulatory rather than practical. The parent refers work to that entity, and the rules governing the work require the recipient to be free to choose among providers, which means the organization making the referral can't own one of them. That is a compliance constraint driving a technical decision, and it changes how you set things up.
When an entity has to be arm's length, you don't just give it a separate tenant and call it done. You want its data, its user directory, and its administration kept distinct so that on paper and in practice it isn't an extension of the parent. Shared logins, shared file stores, or a shared admin who quietly controls both can undercut the independence you're trying to preserve. If a regulator or auditor looks, the separation needs to be real, not cosmetic.
The holding-company layer
Once you're running several entities, someone eventually asks how to see across all of them without merging them. That's the holding-company question. A parent entity sits on top, the operating companies roll up to it, and shared services (IT being a big one) live at the parent and get delivered down to each company.
The upside is that your technology team, your reporting, and your standards live in one place and get applied consistently. Each new company you launch inherits a known setup instead of getting reinvented. High-level reporting rolls up cleanly because the structure was designed for it. The one caveat: the entity that has to stay independent stays outside that umbrella. It can share nothing that would compromise its independence, even if that means a little duplicated effort.
Building your own internal IT as a shared service
The other move worth flagging: the client is turning its internal IT team into something that functions like an internal service provider to each entity. Foundational staff support everyone; specialists get added as the workload grows; outside help fills the gaps that don't justify a full-time hire yet. That's a sensible way to scale when you're growing faster than you can staff, and it pairs well with a co-managed arrangement where an outside partner flexes up and down against real project load instead of a fixed headcount.
If you're launching entities faster than you can plan them
Structuring IT across a growing family of companies is mostly a set of decisions made early: where identities live, which boundaries are real, what rolls up to a parent, and which entity has to stand alone. If you're spinning up new LLCs and wondering how to keep them clean without drowning in overhead, we're happy to talk it through and sketch out what a workable structure looks like for your situation.