PDF Security & Access Issues

How to Fix Adobe Acrobat Reader Sending Editable PDFs Instead of Flattened Copies

Chanuka Geekiyanage Oct 19, 2026 868 views

Question details

The user needs to share PDFs as non-editable copies because the application is incorrectly sending original, editable files after a recent update.

How to Fix Adobe Acrobat Reader Sending Editable PDFs Instead of Flattened Copies

Product: Adobe Acrobat Reader
Device & OS: not provided
Scenario: Sharing a PDF form or document with recipients via email or link while preventing them from altering the form fields or text.
Observed behavior: The option to send a flattened copy is missing or disabled, resulting in recipients receiving fully editable PDF files.

Before you start

Before modifying your application preferences, make sure your Adobe Acrobat Reader is updated to at least version 18.12.00, as older builds may have known bugs related to PDF flattening.

Solution 1Recommended

Update Adobe Reader and Enable the Flattening Option

Updating to a newer software version and manually turning on the PDF flattening preference ensures your documents are shared securely as static files.

Software updates often change default settings or patch known sharing bugs. By ensuring you are on version 18.12.00 or newer, you can restore the missing option to send PDFs as flattened copies.

Check for software updates

Open Adobe Acrobat Reader, click on 'Help' in the top menu bar, and select 'Check for Updates'. Follow the prompts to install version 18.12.00 or later.

Access application preferences

Navigate to 'Edit' > 'Preferences' on a Windows PC, or 'Acrobat Reader' > 'Preferences' if you are using a Mac.

Enable PDF flattening

Locate the sharing or security category in the left sidebar. Look for the option to send a flattened or non-editable copy when sharing, and check the box to enable it.

Save and test

Click 'OK' to save your new preferences. Open an editable PDF and use the share icon to verify that the recipient now receives a non-editable version.

Update Adobe Reader and Enable the Flattening Option

Verify your current version: You can check your exact software version before updating by clicking on 'Help' > 'About Adobe Acrobat Reader'.

Secure PDF Sharing with WPS Office

Flatten and Share PDFs Securely with WPS Office

Avoid the risk of sending editable documents by using WPS Office to easily flatten and secure your PDFs. WPS Office provides built-in, user-friendly tools to lock forms and convert interactive elements into static text before you share them.

1. Open your PDF: Launch WPS Office and open the editable PDF form or document you wish to flatten.
2. Access security tools: Navigate to the 'Protect' or 'Tools' tab on the top ribbon menu to access the document security options.
3. Flatten the document: Use the 'Print' function and select the 'WPS PDF' virtual printer to print the file as a new, flattened PDF, or use the 'Export to Picture' feature.
4. Save and share safely: Save the newly generated file. All interactive layers are now merged into the background, making it safe to send.

Easily flatten PDF forms to prevent unwanted edits from recipientsFully compatible with standard Adobe PDF formats and extensionsLightweight application that opens and processes large documents quicklyAdvanced file encryption and password protection features available

microsoft office alternative - wps office

Frequently Asked Questions

What does flattening a PDF mean?

Flattening a PDF merges interactive elements—such as form fields, digital signatures, and layered annotations—into the main background of the document. This process makes the data static, preventing recipients from altering the information.

Can a flattened PDF be unflattened by the recipient?

No. Once a PDF is completely flattened and saved, the interactive fields are permanently converted into standard text and images. They cannot be restored from that specific file, so you should always keep a backup of your original editable version.

Why did my Adobe Reader stop flattening PDFs automatically?

Major software updates can sometimes reset user preferences or change default application behaviors. Updating to a newer patched version (like 18.12.00) and manually re-enabling the flattening option in the Preferences menu usually resolves this issue.

How can I tell if my PDF is still editable before sending it?

Open the PDF document and try clicking on the text or form fields. If you see a blinking text cursor or are able to type new information, the document is still editable. In a properly flattened PDF, you will not be able to interact with any fields.

PDF Troubleshooting