File Sharing Problems

How to Stop Office for Android from Overwriting Shared NAS Files

Ayan Masood Oct 10, 2026 869 views

Question details

The user wants to prevent the Office app on an Android tablet from syncing older cached files to a shared NAS drive and overwriting more recent changes made on a PC.

How to Stop Office for Android from Overwriting Shared NAS Files

Product: Microsoft Office for Android
Device & OS: Android
Scenario: Accessing and viewing files stored on a shared NAS network drive from an Android tablet.
Observed behavior: The Office app uploads an older, cached copy of a document and overwrites newer changes made from a PC, even when the AutoSave feature is explicitly disabled.

Before you start

Ensure you have backed up the most recent versions of your important files from your PC or NAS drive to a separate local folder before modifying network permissions or app accounts.

Solution 1Recommended

Sign Out of Your Microsoft Account in the Office App

Signing out of your Microsoft account on the Android app restricts it to a view-only mode, which stops background uploading and prevents unintended overwrites.

This is the safest workaround for Android tablets. Without an active account session, Microsoft Office is typically limited to viewing files and cannot sync cached edits back to your NAS drive. Keep in mind that you will frequently see a sign-in banner, which you should ignore.

Open the Office App

Launch the Microsoft Office or Excel app on your Android tablet.

Access Account Settings

Tap on your profile picture or the account icon located in the top-left corner of the home screen.

Sign Out

Select 'Sign Out' and confirm the action. Do not sign back in when prompted by the app.

Read-Only Mode Activated: Your app will now function primarily as a document viewer, keeping your NAS files safe from background syncs.

Solution 2

Restrict NAS Folder Permissions to Read-Only

Modify your NAS drive settings to grant only read access to the credentials used by your Android device.

Solution 3

Use a Dedicated Read-Only Viewer App

Bypass the Microsoft Office sync engine entirely by using a third-party app designed exclusively for viewing documents.

Free Microsoft Office alternative

Try WPS Office for Safe File Viewing on Android

If Microsoft Office continues to unexpectedly overwrite your shared network files, consider switching to WPS Office. It provides a lightweight, secure environment for accessing your NAS files without aggressive background syncing.

1. Download WPS Office: Install WPS Office for Android directly from the Google Play Store.
2. Access your NAS: Connect to your network drive via your preferred Android file manager.
3. Open Safely: Tap your document and select WPS Office as your default viewer to read your files without risk of syncing errors.

Free and lightweight Office alternative for AndroidFully compatible with Microsoft Word, Excel, and PowerPoint formats (.docx, .xlsx, .pptx)Safely view network files without unexpected background overwritesSeamless migration with a familiar, user-friendly interface

microsoft office alternative - wps office

Frequently Asked Questions

Why does Office for Android overwrite newer files on my NAS?

Office for Android sometimes caches older versions of a file locally on your tablet. When it detects a network connection, it may attempt to push this cached version back to the NAS, mistakenly overwriting more recent changes made by other devices like your PC.

Will turning off AutoSave fix the overwriting issue?

Not necessarily. Many users report that turning off AutoSave on Android does not completely stop the app from syncing cached files back to a shared drive. Signing out of your account or using read-only permissions is a much safer workaround.

Can I permanently hide the sign-in banner if I stay signed out?

Unfortunately, Microsoft Office frequently prompts users to sign in to unlock editing features, and there is no built-in setting to permanently dismiss this banner. Ignoring it is currently the only way to ensure your files remain safe from background syncing.

Document & File Issues