How to Share Files Securely

How to Share Files Securely in OneDrive, SharePoint and Teams

Sharing files is something we all do daily — but when it’s not done securely, it becomes one of the easiest ways for sensitive data to leak outside your business.
With Microsoft 365, there are several ways to collaborate and share information safely — but each tool (OneDrive, SharePoint, and Teams) has its own purpose and best practice.

We’ll show you how to keep your business data protected while still enabling your team to work efficiently.

1. Understand Where to Store Before You Share

Before sharing anything, make sure your files live in the right place:

  • OneDrive – your personal workspace in Microsoft 365. Use this for files you own or are currently working on before sharing them with others.

  • SharePoint – the team’s shared library. Documents stored here belong to the team or department, not the individual.

  • Teams – built on SharePoint. Any file shared within a Team or Channel is automatically stored in its connected SharePoint library.

Tip:
If the document is for long-term collaboration or belongs to a project or department, store it in SharePoint or Teams, not in your personal OneDrive.

2. Use Sharing Links Wisely

Microsoft 365 makes it easy to share links instead of attachments — but not all links are equal.

When you click Share, you’ll see options like:

  • People with existing access – safest for internal collaboration.

  • People in [Your Company] – allows anyone in your organisation to view or edit (be cautious).

  • Specific people – best for sending to chosen colleagues or external partners.

Always select Specific people for sensitive information and set an expiry date for external links.

Bonus tip:
Add “view only” restrictions and block downloading if recipients don’t need to edit the file.

3. Secure External Sharing

Sometimes you need to share with suppliers, partners or clients. Here’s how to do that safely:

  • Choose Specific people and enter their email address.

  • Require them to authenticate before accessing.

  • Set an expiry date on the link.

  • Disable editing or downloading unless absolutely necessary.

If you regularly share externally, your IT provider (that’s us!) can configure company-wide policies that limit who can share outside the organisation and how.

4. Control Permissions in Teams

In Microsoft Teams, file permissions are tied to the underlying SharePoint site.
Everyone in the Team can access files by default — so avoid posting highly confidential files in public or company-wide Teams.

For sensitive documents:

  • Create a private channel for specific members.

  • Store restricted files in a separate SharePoint library with tighter permissions.

Remember: Deleting a file in Teams deletes it from the connected SharePoint library too.

5. Protect Data with Sensitivity Labels

Microsoft 365 allows you to apply Sensitivity Labels to documents and emails.
These labels automatically enforce rules like:

  • Encryption

  • Watermarking

  • Restrictions on forwarding or copying

For example, label a financial report as “Confidential – Internal Only”, and Microsoft 365 will ensure it can’t be shared externally by mistake.

If your organisation isn’t yet using labels, ask your IT partner to enable them through Microsoft Purview — it’s an excellent way to automate data protection.

6. Monitor and Manage Access Over Time

Even with good habits, links and permissions can drift over time.
Regularly review:

  • Who has access to your shared folders and files

  • Whether external guests still need access

  • Which sharing links have expired

Microsoft’s Access Review and Audit Logs in the admin centre help identify old links or risky sharing behaviour.

7. Educate Your Team

Technology helps, but human awareness closes the gap.
Train your team to:

  • Check link settings before sending

  • Avoid personal email for business files

  • Report suspicious access requests immediately

Better-IT can help by running usecure awareness training and providing Human Risk Reports that highlight where extra attention is needed.

Final Thoughts

Microsoft 365 makes secure collaboration possible — but only if you set the right boundaries.
By using OneDrive for personal work, SharePoint and Teams for team files, and enforcing clear sharing rules, you keep your data safe while enabling smooth collaboration.

Contact us if you’d like more information on how to share files securely or explore how to apply sensitivity labels and external sharing policies across Microsoft 365.
We’ll help you make collaboration secure, seamless and scalable.

You can also download our guide on file sharing and send it throughout your team.