Microsoft 365 vs Office 365: What You’re Actually Paying For

If you’ve ever seen “Office 365” on an old invoice and “Microsoft 365” on a newer one and wondered whether you’re paying for the same thing twice, you’re not imagining it. The rename genuinely happened, it genuinely wasn’t universal, and both names are still floating around in 2026 for slightly different reasons. Here’s what actually changed, what didn’t, and what’s worth checking on your own subscription.

The Rename, and Why It Wasn’t Straightforward

Microsoft renamed Office 365 to Microsoft 365 back in April 2020, starting with home and personal subscriptions, then most small and medium business plans. By 2022, the “Office 365” name had been fully retired for business plans too. If you signed up any time in the last few years, you’re almost certainly on a Microsoft 365 plan, Business Basic, Business Standard, Business Premium, or Apps for Business, even if you still casually call it “Office 365” out of habit.

Nothing about the actual software changed because of the rename. Word, Excel, PowerPoint, Outlook, Teams, SharePoint and OneDrive all carried over exactly as they were. The point of the new name was to reflect that the subscription had grown well beyond the original Office apps, adding cloud storage, security tools, and device management alongside them.

Where “Office 365” Is Still a Real, Current Product

Here’s the part that catches people out: the rename wasn’t applied everywhere. Microsoft kept the “Office 365” name specifically for its enterprise-tier plans, Office 365 E1, E3, and E5. These are still genuine, current, purchasable products in 2026, not old legacy licences someone forgot to update. If your business is on one of these, “Office 365” on your invoice isn’t a mistake or an outdated relic, it’s a deliberate product line that sits alongside, and is genuinely different from, Microsoft 365’s enterprise plans.

The practical difference at enterprise level is scope. The Office 365 enterprise plans cover the apps and core services. The Microsoft 365 enterprise plans add further layers on top, device management, and more advanced security and threat protection. Neither is “the old one” and “the new one,” they’re two different tiers that happen to share history and branding confusion.

A Third Name in the Mix: “Microsoft Office”

To add one more layer, “Microsoft Office” still exists too, as a separate, one-time-purchase product line (Office 2021, for example), distinct from the Microsoft 365 subscription entirely. If you bought a copy of Office outright rather than paying monthly or annually, that’s what you’re on. It gets the apps but not the ongoing updates, cloud features, or security tools that come bundled with a subscription. Worth knowing if you’re trying to work out which category your own setup actually falls into.

What Actually Matters More Than the Name

Realistically, the name on your invoice matters less than which tier you’re actually paying for. Business Basic is the one that catches people out: it includes Word, Excel, Outlook and the rest, but only as web and mobile versions, there are no installable desktop apps at all. Business Standard is the first tier that adds the proper desktop applications you can actually install on a PC. The jump into Business Premium and the higher enterprise tiers is where the real security value sits for most businesses, device management, stronger identity protection, and better default security, rather than anything to do with the apps themselves.

Pricing changes periodically, and Microsoft has adjusted several tiers within the last year, so we’d rather give you a straight answer based on your actual setup than publish a number here that’s gone stale by the time you read it. If you’re not sure which plan you’re on, or whether it has the security features it should, that’s a five-minute check worth having someone actually do for you.

Where CCSW Comes In

Whichever name is on your subscription, we handle the same things either way, licensing, migration, security configuration, and the day-to-day admin of keeping Teams, SharePoint, Outlook and OneDrive actually working the way your business needs them to. Read more about our Microsoft 365 support, or get in touch if you’d like us to check which plan you’re actually on and whether it’s the right fit.