Which Microsoft 365 Licenses Include a 100 GB Outlook Mailbox?
Question details
The user needs to identify which Microsoft 365 subscription plans offer 100 GB of user mailbox storage in Outlook and Exchange Online.
- Product
- Microsoft 365
- Device & OS
- not provided
- Scenario
- Evaluating or upgrading Microsoft 365 subscriptions to accommodate large email storage requirements.
- Observed behavior
- Seeking clarification on licensing tiers because most standard Microsoft 365 subscriptions default to a 50 GB mailbox limit.
Verify your current Microsoft 365 subscription tier and existing mailbox usage in the Microsoft 365 admin center before purchasing an upgrade.
Upgrade to Microsoft 365 Enterprise E3 or E5
Microsoft 365 Enterprise E3 and E5 are the primary subscription licenses that natively provide 100 GB of primary mailbox storage.
While most Microsoft 365 Business plans (Basic, Standard, and Premium) are capped at 50 GB per mailbox, the Enterprise tiers are designed for larger organizations and offer double the primary storage capacity, alongside auto-expanding archive capabilities.
Log in to the Microsoft 365 admin center using an account with Global Administrator or Billing Administrator privileges.
Navigate to the 'Billing' section in the left-hand menu and select 'Your products' to see your active subscriptions.
If you are on a Business plan, go to 'Purchase services', locate Microsoft 365 Enterprise E3 or E5, and follow the checkout process to upgrade the required users to the 100 GB mailbox tier.
Purchase Exchange Online Plan 2 (Standalone)
If you do not need the full suite of Enterprise E3/E5 features, you can upgrade an individual user's mailbox to 100 GB by adding an Exchange Online Plan 2 license.
Reduce Licensing Costs with WPS Office
Upgrading Microsoft 365 licenses to Enterprise tiers just for larger Outlook mailboxes can significantly increase your IT budget. You can offset these costs by migrating your standard document, spreadsheet, and presentation tasks to WPS Office, a highly compatible, free alternative to the Microsoft Office desktop suite.
Frequently Asked Questions
What is the standard mailbox size for Microsoft 365 Business Premium?
Microsoft 365 Business Premium, along with Business Basic and Business Standard, provides a default primary mailbox limit of 50 GB per user.
Does the 100 GB limit include the archive mailbox space?
No. The 100 GB limit applies strictly to the primary mailbox. Licenses like Enterprise E3, E5, and Exchange Online Plan 2 also include an auto-expanding In-Place Archive that provides up to 1.5 TB of separate archive storage.
Can I increase my mailbox size beyond 100 GB?
No, 100 GB is the maximum primary mailbox size available in Microsoft 365. If a user reaches this limit, they must delete old emails or utilize the In-Place Archive feature to free up primary mailbox space.
How long does it take for the 100 GB limit to apply after upgrading?
Once the Enterprise E3, E5, or Exchange Online Plan 2 license is assigned to the user, the mailbox quota increase typically takes effect within a few minutes, though it can occasionally take up to 24 hours to fully propagate.
