Maximum number of My Sites in Sharepoint Online subscriptions

Some time ago I needed to evaluate maximum number of My sites which can be created in Sharepoint Online. As official SharePoint Online: software boundaries and limits page doesn’t explicitly mentions this limit (instead it says about storage limit for personal sites) I will share results of this investigation here.

Above page contains the following limits depending on your plan:

• Office 365 Small Business plan:
• Number of site collections per tenant: 1
• Number of users: 25
• Office 365 Midsize Business plan:
• Number of site collections per tenant: 20 (other than personal sites)
• Number of users: 250
• Office 365 Enterprise, Education, and Government plans:
• Number of site collections per tenant: 10000 (other than personal sites)
• Number of users: more than 500000 (with possibility to increase the limit)

For Office 365 Midsize Business and Office 365 Enterprise, Education, and Government plans which have more than 1 site collection, it explicitly says that limitation on number of site collections doesn’t affect personal sites (My sites). At the same time it doesn’t explicitly says about limitation on number of personal sites. However in “Additional information about OneDrive for Business limits” section it says the following:

“Each user in SharePoint Online for Office 365 gets an individual storage allocation of 1 TB for personal site content (100 GB for government plans). Personal sites include the user’s OneDrive for Business library, a Recycle Bin, and personal newsfeed information.”

I.e. it looks like that limitation on number of My sites in Sharepoint Online = limitation on number of users (see above). So for Office 365 Small Business plan we may have up to 25 My sites, for Office 365 Midsize Business plan – 250 My sites and for Office 365 Enterprise, Education, and Government plans – 500000 (with possibility to increase the limit).