Office 365 Reaches 180 Million Monthly Active Users

Growth in Office 365 Users Since November 2015
Growth in Office 365 Users Since November 2015

Office 365 Powering Ahead

As is usual in Microsoft’s April quarterly report (for Q3 FY19), they gave a new number for Office 365 users. In the earnings call, CEO Satya Nadella said that “Office 365 commercial now has 180 million users.” This marked an uptick in the monthly gain to around 4.16 million users since the last number (155 million) was reported in November 2018.

I had expected the number to be in the region of 175 million and it’s interesting to see an increase in users gained each month because eight years after its launch, Office 365 is well past the point when easy migrations happen. The uptick might be driven by large organizations moving to the cloud after they have digested what Microsoft is doing (or not doing) with on-premises servers and noted the relative lack of new functionality appearing in Exchange 2019, SharePoint 2019, and Skype for Business 2019 when compared to their cloud counterparts.

Microsoft also said that Office 365 commercial seats grew 27% year-over-year (Figure 1). This confused me a little because the April 2018 number for Office 365 was 135 million and 27% growth would put the new number around 171 million. However, like many numbers presented in Microsoft earnings briefings, we don’t quite know how they are measured, so we must accept the new figure to be 180 million.

Q3 FY19 Highlights for Productivity and Business Processes (source: Microsoft)
Figure 1: Q3 FY19 Highlights for Productivity and Business Processes (source: Microsoft)

Strong Growth for Enterprise Mobility and Security,(EM+S)

Another figure that attracted my attention was the assertion that “Our EMS install base reached 100 million.” The reason why this is important is that it indicates that a large proportion of the Office 365 base also buys EM+S; it also implies that an even larger proportion of the enterprise Office 365 base buys EM+S. I’m sure some customers buy EM+S without Office 365 but I’m unsure why they would do so. The growing EM+S base also indicates that Microsoft is having some success in moving customers over to Microsoft 365 plans. Microsoft CEO Amy Hood noted that “Office 365 commercial seats grew 27% and benefited from the strong performance of our Microsoft 365 academic offers.”

Success for Outlook Mobile Too

Satya Nadella also said that “the Outlook apps on iOS and Android surpassed more than 100 million users for the first time this quarter.” From one perspective, Outlook reaching this milestone shouldn’t be surprising because:

  • Outlook mobile can be used by both cloud and on-premises Exchange. Although the Exchange Online base is obviously growing in line with Office 365, there’s still a lot of Exchange on-premises in use.
  • Outlook mobile is acknowledged as a great client for other mail servers, like Gmail.
  • Mobility is hugely important for users.

But if you think about things a little deeper, what the data might be telling us is that an increasing percentage of Office 365 users are moving away from the mail apps built into iOS and Android to use Outlook instead. This is sensible because Outlook is a far more feature-rich client. The connectivity architecture used by Outlook mobile enables features like the Focused Inbox (hated by some), encrypted email, and smart calendaring. Native mail apps use the now-outdated ActiveSync or IMAP4 protocols and will never have access to this functionality.


We keep an eye on Office 365 numbers because we like to know what’s happening with the suite and the surrounding ecosystem. It’s an evolving world. See Chapter 1 of the Office 365 for IT Pros eBook for more information about the commercial success of Office 365. Outlook Mobile is covered in Chapter 10, and EM+S in Chapter 18.

94 Replies to “Office 365 Reaches 180 Million Monthly Active Users”

  1. Tony, I agree the 27% growth rate from April 2018 doesn’t match 180 million in April 2019. To 180 million is a 33% growth. Unlike the previous growth rates, this one doesn’t add up properly. In my ongoing tracking model, the other rates have matched … so something weird / different / “new maths” is going on here. We’ll keep watching.

  2. Unless we’re reading that line wrong, since it is about revenue growth by 30%, not seat growth. Note the comma after “seats growth.” Perhaps what that line is actually saying is “Office 365 commercial revenue grew 30%, driven by growth in Office 365 commercial seats (27% of the total revenue gain) and growth in revenue per user (the other 3% due to users migrating to more expensive Office 365 plans).”

    1. Certainly Microsoft has had a huge focus on upgrading customers to higher plans over the last few years… and the more people who use Microsoft 365, the better for their cloud revenues.

  3. Everyone is using Microsoft Excel to place their raw data and to analyze it using different charts and graphs offered by Excel. But there are many other tools available to do their tasks.

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