Security incidents inside Microsoft 365 typically trace back to something mundane, a default setting nobody changed, or a permission that was never revoked. The software usually isn’t the problem. What’s exposed is whatever configuration got left behind once the initial setup was finished, quietly ageing while the rest of the business kept changing around it. It stays invisible until something goes wrong or until an insurer, auditor, or customer asks a question the business can’t answer with confidence.
One login now holds everything together
A typical working day shows how far this has gone. An employee signs in once with a Microsoft identity, then sends email, opens shared documents, joins a Teams call and connects to whatever else the business runs through the cloud, from expense software to e-signature tools, often without a second login. That single sign-in now does the work that used to be spread across a server, a filing cabinet and a handful of separate systems.
Microsoft 365 has taken on the central role those systems used to hold, without businesses updating how much attention they give it in return. Security thinking built around a server room, patched and checked to a schedule, doesn’t map cleanly onto an environment that changes every time someone joins, leaves, changes role or connects a new app.
Nothing stays put for long
Few businesses would set up their bookkeeping once and assume the numbers would stay accurate no matter what changed around them. Microsoft 365 security tends to get treated exactly that way. It gets configured properly when it’s first set up, sometimes as part of onboarding with an IT partner, and then left to run on the assumption that if nothing looks broken, nothing has changed.
In practice, little about a live Microsoft 365 environment stays fixed. A role change doesn’t always trigger a review of what access should change with it, so old permissions often just sit alongside the new ones. A third-party app connected for a single project can keep read access to email and files long after the project and the app itself are forgotten. Each of these changes happens without an alert. The distance between how the environment is set up and how well it’s protected grows a little wider every time, and it stays invisible from the outside until someone is forced to look.
The bar keeps moving too
Staff changes aren’t the only source of drift. What counts as good practice for Microsoft 365 changes as well. Take Microsoft’s own identity secure score. It grades how a tenant (the private area of Microsoft 365 that holds one organisation’s users, settings and data) is configured and recalculates roughly every 24 hours as recommended actions are reassessed. The Center for Internet Security refreshes its Microsoft 365 Foundations Benchmark on a regular basis too, with its latest major revision landing in 2026 carrying a substantial round of new and updated controls. A setting that met best practice eighteen months ago may no longer be considered sufficient today, even if nobody in the business has touched it since.
Microsoft won’t do this part for you
This isn’t a reason to shift the blame onto Microsoft, either. The National Cyber Security Centre’s guidance on cloud security draws a clear line between provider and customer. Microsoft secures the platform itself. Configuration, access decisions and day-to-day use remain down to the business using it. Microsoft can supply the tools and the recommendations. It can’t decide who still holds admin rights inside a tenant or which old third-party apps should still have access to email and files. Owning this doesn’t need a background in IT. It needs someone at the top of the business treating Microsoft 365 configuration as a standing item worth checking on a schedule, the same way a lease renewal or an insurance policy gets reviewed periodically.
You can’t fix what you haven’t looked at
Deciding what to do about any of this depends on an accurate, current understanding of the environment. Assumptions based on how it was originally set up, or how it’s supposed to work in theory, don’t hold up over time. A Microsoft 365 security review is how that understanding gets established.
This is the reasoning behind SolCo’s complimentary Microsoft 365 Security & Compliance Review. It looks at how the Microsoft 365 environment is configured right now, covering identity and access security, email protection, data sharing and device security, alongside the wider governance controls that sit around all of it. Findings are reviewed against the CIS Microsoft 365 Foundations Benchmark Level 1, a set of configuration standards built in partnership with Microsoft, and written up as a report aimed squarely at business decision-makers.
A review like this doesn’t make a business secure or compliant on its own, and being assessed against the CIS benchmark is not a substitute for certification. It gives leadership a clear, current view of the environment, along with a sensible order of priorities for whatever needs attention. From there, what happens next is an informed decision the business can make for itself. SolCo holds Cyber Essentials Plus certification and aligns its own security programme with the NCSC’s Cyber Assessment Framework, so clients are held to the same standard SolCo applies to its own environment.
People join, change roles and leave. New integrations get added along the way. All of it keeps moving in the background, with or without anyone watching. Reviewing Microsoft 365 once and assuming it still holds years later is how a well-run business across Reading and the Thames Valley ends up trusting an environment that no longer matches how it was originally set up.
Book your complimentary Microsoft 365 Security & Compliance Review to find out exactly how your own Microsoft 365 environment is configured today, in plain business terms.
