I'm need to block a specific file format in a library of SharePoint online site (o365). I have activated RMS feature in admin & in Admin-> sharepoint-> settings too.

What's the next step or procedure?

Or is there a feature or method where I can allow the users to add only documents or Pdf file format ?

  • Do you want people to stop saving a certain format, or open files (in that format) that happen to be there already. Commented Aug 30, 2016 at 9:59
  • They are not allowed to upload other formats, except documents or pdf (depending upon the situation). For eg: in one library only pdf and in another library only documents.
    – rakesh s
    Commented Aug 31, 2016 at 10:05

2 Answers 2


There is no OOTB facility with SharePoint Online to restrict specific file extensions in SharePoint Online. The only ways are:

  • Create an event handler which will check the file extension.
  • Create a workflow for the same.

I had a look around and can't see any indication that this is editable - seems like another thing MS hide from us.

From looking at the IRM options on a library it doesn't seem like blocking certain file types is an option, just that you can block any non-IRM compatible files being uploaded.

My suggestion would be a workflow that auto-runs on each item and if it doesn't match the given type, auto-deletes the document. Little bit clunky but it would do the job, just keep an eye on resource usage if you're dealing with a ton of documents.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.