How we cut a file-sharing subscription by 90 percent

A customer was renting a second building to meet their partners in. Not literally, but that’s the shape of it. They had a separate external system, 600 euros a month, whose only job was to let partners and clients upload documents during a tender process. Meanwhile the Microsoft 365 they already paid for, the one every employee logged into every morning, could do the same thing and mostly sat unused for it.

That’s the real problem, and it’s rarely a technology one. The portal wasn’t bought because Microsoft 365 couldn’t do external file exchange. It was bought years earlier, quickly, to solve one urgent tender, and then it simply stayed. Nobody ever went back to ask whether the capability they were now paying a subscription for was already included in a licence they held. That question is the whole job. The technology after it is almost easy.

What the subscription was actually doing

Strip away the branding and the external system did three things: let an internal person open a space for a specific tender, let named external partners upload files into only that space, and keep each tender’s documents separate from every other one. That’s it. Three functions, 600 euros a month, plus the quiet cost of one more vendor, one more login for partners and one more system nobody internally really owned.

None of those three functions are exotic. They’re what SharePoint and external sharing were built to do. The only thing missing was a front door simple enough that an internal user could open a new tender without thinking about site permissions, and an external partner could upload without a support call.

What we built instead

We put a Power App in front of SharePoint, surfaced inside Teams where people already work. An internal user opens the app, creates a new project, and the app provisions the SharePoint structure and the correct permissions behind the scenes. External partners get invited to that project and only that project, they upload their documents, and everything stays scoped to the tender it belongs to.

The person creating a tender never touches a permission setting. The external partner never sees anything except the project they were invited to. The complexity is still there, it’s just moved into the app instead of landing on the user. That’s usually the difference between a system people actually use and one they quietly work around.

The whole thing was in production in four weeks.

What it costs, honestly

This is where it matters to be precise, because “we replaced it for almost nothing” is only true under a condition. The Power App runs on standard connectors, SharePoint and Teams, which are covered by the Microsoft 365 licences the customer already owned. External partners upload through SharePoint external sharing, which doesn’t add a per-user licence for the volume of guests involved here. That’s why the running cost dropped by roughly 90 percent, the subscription went away and what replaced it was mostly capability they were already paying for.

The condition is this: the moment a build like that needs premium connectors or Dataverse, the licensing math changes, and a per-app or per-user Power Platform licence enters the picture. It still tends to beat a 600-euro external subscription, but it’s no longer free. Anyone promising 90 percent without checking whether the design stays on standard connectors is guessing. In this case it did, deliberately, because keeping it there was worth more than any premium feature would have added.

There’s also a real trade-off on the other side of the saving. The subscription was somebody else’s software to maintain. Now it’s ours to own. That’s the right call here, because the build is small, standard and understandable, but “we saved 90 percent” always quietly means “we took on the maintenance.” That’s only a good deal when the thing you built is simple enough to stay maintainable.

What I’d actually recommend

Before renewing any SaaS subscription that exchanges files, collects documents or gives partners a place to upload, check whether the capability already exists in the Microsoft 365 you pay for. Often it does, and the only thing missing is a simple front end. Build that front end on standard connectors and keep it small enough that owning it is genuinely cheaper than renting it. And be honest about the maintenance you’re taking on, because a 90 percent saving that turns into a system nobody can operate isn’t a saving, it’s a deferred cost. In this case it was neither deferred nor complicated: four weeks, standard tools, and a subscription that stopped renewing.