You send a PDF you can take back by sharing it as a tracked link through a hosted platform, not as an email attachment. An attachment becomes a second, independent copy the moment it lands; a link points at one hosted copy, so revoke the link and the file stops opening.
Steps
- Upload the PDF to a [room](/glossary/virtual-data-room/) rather than attaching it to an email. This keeps a single hosted copy that you control, for the reasons our piece on why emailing a contract as an attachment is so risky sets out in more detail.
- Choose who can open it. On Plus and above, choose "Anyone who verifies an email address" and the viewer is emailed a six-digit code to enter before the file opens. On the free tier, choose "Anyone who gives an email address", or switch on "Only the people I name", which verifies each named person the same way on every plan. On Pro and Business you can also require an NDA first.
- Create the link. Select Share on the document, choose the settings, select Create link and copy it. Send that link in your email or message, never the PDF file itself.
- From Plus, set an expiry. Under "How long it lasts", choose a date (or a number of opens) so access closes on its own without you having to remember.
- Watch the activity. Open the document's Activity tab to see who opened it, when, for how long and how far they got. From Plus you also see the time on each page.
- Revoke when you need to. If the deal falls through, you sent the wrong version, or the recipient no longer needs access, open the Shares tab, find the link and select Revoke. Anyone opening it is refused, and anyone reading at that moment loses access within moments.
Edge cases and what to check
If the recipient already downloaded the PDF before you revoked the link, that copy is gone from your control. Revocation stops future access; it does not reach into a device that already has a saved file. Set Downloads to Off in the share settings, on any plan, if the document should be read rather than saved: there is no download button and the download is refused, though the document is still shown in their browser.
If you are used to sharing from a generic cloud drive, our comparison of a data room against a shared drive covers why the two behave differently once you need to take a document back. The free tier gives three rooms and twenty five active links, forever, with no card required, which is enough to try this on a real document today, and revoking and tracking work on it in full. NDA acceptance is on Pro and Business, and a per-viewer watermark on screen is on by default on every plan; the watermark deters leaks and helps you identify the source of a screenshot, though it does not stop one, and downloads are not watermarked.
After sending, check three things: that the link opens correctly for a test recipient, that the check you chose (an email address, an emailed code or an NDA) actually appears before the document, and, if you set one, that your expiry date matches how long the recipient genuinely needs access. A link left open indefinitely is the same risk as an attachment, just delayed.
If your current tool cannot do this
Plenty of everyday tools cannot offer a genuine take-back, which is the same problem covered in how you un-send a document you have already shared. The test is simple: does the recipient ever hold an independent copy of the file, or only access to one hosted copy?
- If the tool works by attaching a file to an email, there is no way back. The file is a copy from the moment it sends.
- If the tool is a generic cloud drive link, remember that disabling the link cannot reach a copy someone already downloaded, so check whether you can keep downloads off in the first place.
- If "revoke" only takes effect at the recipient's next login rather than immediately, a person already inside the document keeps reading until they leave.
- If the platform cannot show you whether the file was actually opened, you have no way to judge how much damage a mistake caused.
Any tool that hosts the file, can check who is opening it, and revokes immediately clears this bar. 99 Data Rooms hosts the file and revokes a link immediately on every plan, adds verified-email access from Plus, and our comparison of what a data room can do that a Dropbox link cannot sets out the same test against a shared-drive tool.
Attachment vs revocable link, side by side
| Email attachment | Revocable link | |
|---|---|---|
| What the recipient holds | An independent copy on their device | Access to one hosted copy |
| Can you take it back | No, once it lands | Yes, at any point |
| Can you see if it was read | No | Yes: who opened it, when and how far they got; time on each page from Plus |
| Can you fix a wrong version | Only by sending a follow-up | Yes, replace the file behind the same link |
This table is the whole argument in one place. Every advantage in the right column depends on the file never leaving your control in the first place, which is why the platform you choose matters more than any setting inside it.
Frequently asked questions
Can I take back a PDF I already emailed as an attachment? No. Once an attachment sends, the recipient's email client has downloaded its own independent copy. Message recall features rarely work outside the same email system, and never once a file has been opened or saved. The only fix going forward is to stop sending PDFs as attachments and share them as revocable links instead.
Does revoking a link delete the file the recipient already saw? No. Revocation stops the link from opening again. If the recipient already downloaded a copy before you revoked it, that copy is unaffected. To prevent downloads, set Downloads to Off on the link before you send it.
What is the difference between revoking and setting an expiry? Revoking is a manual, immediate action you take when something changes, on every plan. Expiry, from Plus, is a date you set in advance so the link closes itself even if you forget. Where you have it, use expiry as the default and revoke as the override for anything unplanned.
Do I need a paid plan to revoke a share link? No. Revoking a link is on every plan, including the free tier with three rooms and twenty five active links and no card required. Plus adds verified email, passcodes, expiry and page-by-page analytics; Pro and Business add NDA acceptance and Office uploads, and per-viewer watermarks are on by default on every plan. Revocation works the same on every plan.
How do I know if someone read the PDF before I revoked it? Check the document's Activity tab, which shows who opened it, when, and how far they read; the time on each page is from Plus. That tells you whether the mistake was actually seen before you cut access, which matters more than a click count alone.
Send it so you can always take it back
Share your next PDF through a room instead of an attachment, add e-signature from Plus if it needs signing, and keep the option to switch off access at any point. The free tier covers three rooms and twenty five active links forever, no card needed. Start free and send the next one properly.
Sources
- Revocation, gating and analytics behaviour reflect 99 Data Rooms product facts. Email attachment and recall limitations are general, documented behaviour of standard email clients, not specific to any single vendor.