Office 365 File and Storage Limitations

Blog written by:
Chris Ang
SharePoint Architect


SharePoint started its journey by being a content collaboration tool for teams; from there on, new features were added such as portals, business intelligence (BI) and enterprise content management (ECM). These new features enhanced the user experience and brought in more loyal customers. With the evolution of SharePoint in the cloud with Office 365, teams could collaborate in a connected-world through mobile devices too. Apart from the existing capabilities like Search, Content and Team Sites, new experiences like Office Delve and Office 365 Video were integrated with email, instant messaging and other SharePoint workloads.

What makes SharePoint Online a popular content sharing and collaboration platform is that it is tightly integrate with MS Office and provides a cohesive environment for teams to work together with tools they are already familiar with. SharePoint Online continues to be the number one choice for companies to use as a content management system because of the ease of use. It provides steady hybrid connections between the on-premises and online versions, and its demand continues to grow across organizations.

SharePoint Online Storage Capacity

If you’re a dedicated user of SharePoint Online or still considering migration to Team Sites on Office 365, then this piece of news will surely get you more excited. Microsoft recently made a big announcement (although surprisingly in a very subtle manner) that the SharePoint Online site collection has now increased the storage space limit to 25TB from the existing 1TB limit!

Let’s briefly look at how SharePoint online site collections limit has changed over the years. In 2007, the site collection size limit was 2GB. Then in 2012, the site collection size was increased to 100 GB and in 2014, the limit was increased to 1TB. Now, in September 2016, Microsoft boosted the site collection limit size to 25TB.

Top Six Questions about SharePoint Storage Limits: SharePoint 2007 vs. SharePoint 2010

SharePoint Online announces 1TB site collections and unlimited tenant storage scale

This is going to benefit SharePoint online users for their content management and give them a whole lot of opportunities to use the system in an integrated manner with Office 365 Groups and Team Sites. This space increase is also set to encourage more companies to move their data from on-premises to SharePoint Online and help improve the performance of Groups in Office 365.

Office 365 as a Content Management System

Apart from the storage enhancement, the new update for SharePoint Online will also have deeper integration with Office 365 Groups, such as an automatic Site creation for each Office 365 Group. This will be rolled out to Office 365 First Release customers this month (September 2016).

There are some really cool new features, check out this post as it is a very good overview of these new updates:

New SharePoint and Office 365 users will however need to keep a few things in mind with respect to storage limits in file name, folder name and restrictions on type of files, and email limitations if using Office 365 for email (Exchange Online).

File Name Length Limitations

While migrating to SharePoint Online or OneDrive for Business, users need to remember that SharePoint has certain limitations with regard to the length of the file path and file names. So unless you shorten the names, they could cause issues during migration. The maximum file path within OneDrive for Business is 260 characters.

This gives the actual allowance for the file name to be roughly around 215 (after removing the characters for folder name and URL). Some SharePoint systems have defined a clear limit of 128 characters for file names and 128 characters for folder names; hence, the folder name and file name combinations can run up to 250-260 characters.

(Sources: )

Excel Workbook Size Limitations

SharePoint Online has some file size limits and this depends on your Office 365 subscription type. If your subscription has Power BI for Office 365, then you will be able to work with larger workbooks in a browser window.

Here is a complete list of the limitations for different Office 365 subscriptions:


(Reference: )

File Type Restrictions for Office 365

Although there are no blocked files in OneDrive for Business on Office 365, for security reasons one cannot use certain file names and extensions due to their executable nature. Additionally, the file types that have been blocked on the SharePoint on-premises site, are automatically not allowed for uploading in Office 365.

The file type restrictions are as mentioned below:

  • *.tmp
  • *.ds_store

Also, the following files can’t be uploaded:

  • desktop.ini
  • thumbs.db
  • ehthumbs.db


OneDrive for Business Sync Limitations

OneDrive for Business can be useful, so it is good to be aware of some of the limitations before allowing users to use this feature. I put a summary below gathered from the Microsoft Support site.

Total Number of Synced Items

You can sync up to 20,000 items total across all synchronized libraries. This includes OneDrive for Business libraries, Team Site libraries, or both.

Total Number of Synced Items in a Library

You can sync up to 5,000 items in a SharePoint library. This includes folders and files. In any SharePoint library, you can sync files of up to 2 gigabytes (GB).

Character limit for files and folders

  • In SharePoint Server 2013, file names can have up to 128 characters.
  • In SharePoint Online, file names can have up to 256 characters.
  • Folder names can have up to 250 characters.
  • Folder name and file name combinations can have up to 250 characters.

File Characters Not Allowed When Syncing

The following characters in file or folder names aren’t supported when you sync OneDrive for Business with SharePoint Online:



Additionally, a file or folder name that begins with a tilde (~) isn’t supported.

Folder Names should not Contain

The following folder names can be synchronized in OneDrive for Business and SharePoint Online. However, if they’re synchronized, they may not appear when you view the library on the SharePoint Online or OneDrive for Business webpage.



Files that Cannot be Synced In OneDrive for Business

  • Outlook PST files (that are in use)
  • OneNote Notebooks
  • OneNote Class Notebooks
  • Open Files such as MS Excel files cannot be Synced
  • Libraries that exceed List View Threshold
Office 365 Exchange Email Message Size Limits

While using Office 365 Exchange, there is a maximum message size of 25MB and file attachments of up to 150 MB.
(Source: )

In 2015, this limit was only 25MB wherein large documents could be attached as links. But with the increase in limit now to 150MB, users can now send files as actual attachments.

But you need to know that the Office 365 Exchange uses a policy to control the types of files allowed or blocked as attachments to emails, and whether they can be opened directly or need to be saved before opening. For example, executables are often blocked and there are other types of files but we won’t discuss this in detail in this particular blog.


While there are certain improvements yet to be done, the increase of storage space from 1TB to 25TB comes as a relief for all those who felt limited by the 1TB space. This move by Microsoft will help in easy adoption of SharePoint Team Sites by businesses and new users. These updates show that Microsoft is really focused on making Office 365/SharePoint Online the best platform for online collaboration.


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Chris Ang

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