Share files externally

Who this is for: anyone who needs to send files to a client, vendor, accountant, or contractor.

The short answer

Share a link from OneDrive or SharePoint rather than attaching the file. Set the link to a specific person, add an expiration date, and choose view-only unless they genuinely need to edit. Emailing attachments back and forth creates version chaos and leaves copies you can never retrieve.

Why not just attach it?

An attachment is a copy. The moment it leaves, you've lost the ability to update it, revoke it, or know who has it. Two rounds of edits later, three people are working from three different files and nobody knows which is current. A link stays pointed at one living document.

Sharing a link

1. In OneDrive or SharePoint on the web, or in File Explorer/Finder with sync running, right-click the file or folder and choose Share.
2. Click the current permission setting at the top of the box — usually "Anyone with the link" or "People in [your organization]."
3. Choose Specific people, then enter the recipient's email address.
4. Turn off Allow editing unless they need to make changes.
5. Set an expiration date. Thirty days covers most work.
6. Click Apply, then Send — or Copy link to paste it into your own message.

Choosing the right link type

• Specific people — the recipient verifies their identity or receives a one-time code. Use this by default, and always for anything confidential.
• Anyone with the link — works without sign-in, which also means it works for anyone the link gets forwarded to. Acceptable for a public brochure. Never for client data, financials, or anything with personal information.
• People in your organization — internal only. It will simply fail for an outside recipient, which is a common cause of "your link doesn't work."

Sharing a folder for ongoing work

If you'll exchange files with someone repeatedly — an accountant during tax season, a contractor on a project — share one folder rather than sending links file by file. Both sides drop files in, everyone sees the same contents, and access is removed in one step when the engagement ends.

Turning access off

1. Right-click the file or folder, choose Manage access.
2. Review who has links and who has direct permissions.
3. Remove the ones that are finished.

Worth doing once a quarter on anything sensitive. Links accumulate.

When the recipient can't open it

• They're asked to sign in and have no Microsoft account. That's fine — with a "specific people" link they'll get a one-time passcode by email instead. Tell them to check junk.
• "You need permission." The link was probably set to your organization only, or was forwarded to someone it wasn't issued to. Reissue it to their actual address.
• Their company blocks the link. Some firms filter external sharing links. Ask what method their IT allows rather than falling back to an unprotected attachment.

What not to use

Personal Dropbox or Google accounts, USB drives handed across a counter, and consumer file transfer sites all put business data somewhere you don't control and can't audit. If you're reaching for one because the sanctioned method is awkward, tell us — the awkwardness is a fixable problem.