SharePoint stores PUB files but cannot open or preview them. Since October 1, 2026, Microsoft 365 users no longer have Publisher, so PUB files in SharePoint no longer open in Publisher for most of them. The files are still there. IT admins need a bulk conversion plan now. Two options: Microsoft’s PowerShell script (needs a working copy of Publisher on a Windows Server or workstation, converts to PDF) or Univik PUB Converter (no Publisher required, converts to PDF or DOCX, runs on any Windows machine). To read a PUB file already stored on SharePoint, download it and open it in the free Univik PUB File Viewer on Windows. The PowerShell approach suits scripting-comfortable admins with Publisher available. The converter tool is faster for organisations that no longer have Publisher, which now includes Microsoft 365 users, or that need DOCX output.
Update, 1 October 2026: Publisher has left Microsoft 365
Microsoft 365 users can no longer open PUB files in Publisher, so a PUB file downloaded from SharePoint now opens for almost nobody on a Microsoft 365 desktop. The files in your libraries are not deleted. A batch converter that needs no Publisher, such as Univik PUB File Converter, turns them into PDF or DOCX files you can upload back to SharePoint.
SharePoint Cannot Open PUB Files
Microsoft SharePoint has no PUB file handler. PUB files uploaded to SharePoint appear in document libraries as generic file entries: no preview in the browser, no Open in browser option and no Microsoft 365 application that opens them from SharePoint directly.
This is the same story as Google Drive but with a sharper edge: SharePoint is a Microsoft platform, Publisher is a Microsoft application and yet SharePoint cannot open Publisher files. The PUB format was never integrated into SharePoint’s document handling and with Publisher retired from Microsoft 365 in October 2026, it never will be.
Users who click a PUB file in SharePoint are prompted to download it. To see what a file contains without Publisher, you can open it in an Online Publisher Viewer directly in the browser. Colleagues with a one-off licence for Publisher 2021, 2019 or 2016 can open the downloaded file. Since October 1, 2026, Microsoft 365 subscribers no longer have Publisher, so the download prompt leads to a file they cannot open in it. The lasting fix is to convert the PUB files to PDF so anyone can open them straight from SharePoint.
“SharePoint is where these files go to be forgotten, and since 1 October 2026 most people who open that library have no Publisher at all. Convert in batch now so the next person who needs a file can read it. We have run those batches on PUB and PUZ from every Publisher version and compared the output page by page.”
Nick Rogers
|Founder, Univik, building file conversion tools since 2013
Why This Is Urgent Now
Organisations storing PUB files in SharePoint now face a compound problem, because the October 2026 deadline has passed.
Microsoft 365 subscribers lost Publisher on October 1, 2026. A user who downloads a PUB file from SharePoint now cannot open it in Publisher. The download completes. Windows has no associated application. Some copies of Publisher still opened on October 1 with a “Publisher is retiring” banner, but that is borrowed time.
The Publisher-based route has narrowed. Microsoft’s conversion script needs a working copy of Publisher. With Microsoft 365 users cut off, that route now depends on perpetual licence users (a shrinking group, with support for Publisher 2021 ending on October 13, 2026). The other route is a third-party tool that does not need Publisher.
PUB files are already inaccessible to non-Windows users. Mac users, Chromebook users and anyone accessing SharePoint from a browser or mobile device already cannot open PUB files from SharePoint. Since October 1, 2026, this problem covers most Windows users too.
For the full timeline and licence-type breakdown, see our Microsoft Publisher end of life guide. For the specific question of what happens to PUB files after the deadline, see our PUB files October 2026 guide.
Step 1: Audit Your SharePoint PUB File Inventory
Before any conversion can begin, you need to know what you have. PUB files accumulate across years of SharePoint use in site collections, document libraries, subsites and archived project folders.
Search SharePoint for PUB files. In SharePoint, use the site search with the query filetype:pub to find PUB files across the site collection. This returns results from document libraries the searching user has access to. For a full tenant-wide inventory, use the SharePoint Admin Center or Microsoft Search with admin scope.
Use PowerShell for a complete inventory. A PnP PowerShell or Microsoft Graph script can enumerate all PUB files across all site collections in the tenant. This is the most complete approach for organisations with multiple site collections and large SharePoint environments. Example query using PnP PowerShell: connect to the SharePoint admin centre, iterate site collections and search each for files with .pub extension.
Export the inventory to a spreadsheet. Record the SharePoint URL, site collection, library, folder path and file name for each PUB file found. This inventory is the project plan for the conversion. Share it with the document owners to confirm which files are still active and which are archived.
Step 2: Triage by Priority
Not all PUB files in SharePoint need the same treatment. Use the inventory to categorise files before starting the conversion project.
| Category | Description | Recommended Action |
|---|---|---|
| Active templates | PUB files used regularly to produce new documents | Convert to DOCX (for editing in Word) and PDF (for reference). Rebuild in Word or another tool for ongoing use. |
| Active documents | Current brochures, newsletters, materials still in use | Convert to PDF for distribution. Convert to DOCX if editing is needed. |
| Recent archive | Files from the last 1 to 3 years, occasionally referenced | Convert to PDF and store in SharePoint archive library. Keep original PUB alongside. |
| Deep archive | Files older than 3 years, rarely if ever accessed | Convert to PDF for preservation. Move to a SharePoint archive site with lower visibility. |
| Unknown / owner unclear | Files with no clear owner or last modified date far in the past | Attempt to contact document owners via SharePoint audit trail. If no response within 4 weeks, convert to PDF and archive. |
Method 1: Microsoft’s PowerShell Script
Microsoft provides a PowerShell script (Convert-PubFileToPDF) that uses Publisher’s COM interface to batch-convert PUB files to PDF. The script opens each PUB file in Publisher programmatically, exports it to PDF and closes it, automating what would otherwise be a manual file-by-file process.
Requirements:
Publisher must be installed and licensed on the machine running the script. Without Publisher, the COM interface is not available and the script fails. Since October 1, 2026 that means a perpetual Publisher 2021, 2019 or 2016 installation, or a Microsoft 365 setup where Publisher still launches.
The script must be edited before use to specify the source folder path and output folder path. The Microsoft documentation provides the base script and editing guidance.
The output format is PDF only. The PowerShell script does not produce DOCX output. For DOCX conversion, use Method 2.
SharePoint files must be downloaded to a local or mapped drive before running the script. The script operates on local file paths, not SharePoint URLs.
Practical workflow with PowerShell: Download the SharePoint PUB files to a local folder using SharePoint Sync or manual bulk download. Edit the PowerShell script to point to the local source and output folders. Run the script on a Windows machine with a working copy of Publisher installed. Upload the resulting PDFs back to SharePoint.
Method 2: Dedicated Batch Converter
Univik PUB Converter converts PUB files to PDF and DOCX in bulk on Windows without requiring Publisher to be installed. This makes it applicable in two scenarios where the PowerShell approach fails: organisations where Publisher has already been removed, and Microsoft 365 users, who lost Publisher on October 1, 2026.
Workflow with Univik PUB Converter:
Download PUB files from SharePoint. Use SharePoint Sync to sync the document libraries containing PUB files to a local Windows machine. Alternatively, select files in the SharePoint document library and use the Download option. SharePoint packages selected files as a ZIP. Extract to a local folder.
Load files into Univik PUB Converter. Open the converter, click Add Folder and select the local folder containing the downloaded PUB files. The converter lists all PUB files found, including those in subfolders if the “include subfolders” option is enabled.
Select output format and folder. Choose PDF or DOCX as the output format. Select a local output folder. Enable “preserve folder structure” if the source files were in nested subfolders. This maintains the original folder hierarchy in the output, which makes re-uploading to SharePoint in the correct location easier.
Run the conversion. Click Convert. The converter processes all files and produces a summary report showing successful conversions, failed files and any files that required manual review.
Upload converted files to SharePoint. Use SharePoint Sync or the SharePoint document library upload to push the converted PDF and DOCX files back to the correct SharePoint locations. Preserve the original folder structure from the source.
PowerShell vs Batch Converter: Which to Use
| Factor | PowerShell Script | Univik PUB Converter |
|---|---|---|
| Publisher required | Yes, must be installed | No |
| Output formats | PDF only | PDF and DOCX |
| Technical requirement | PowerShell scripting knowledge | GUI, no scripting |
| Cost | Free (script is from Microsoft) | Licensed software |
| Speed | Slower (opens and closes Publisher for each file) | Faster batch processing |
| Works after October 1, 2026 | Only with a perpetual Publisher copy (or a Microsoft 365 install where it still runs) | Yes, Publisher not required |
| Best for | IT admins with Publisher available and scripting skills | Organisations without Publisher or needing DOCX output |
Step 3: Upload and Manage Converted Files in SharePoint
Upload converted files to the same libraries. Place the PDF or DOCX files in the same SharePoint document library as the original PUB files. Users who navigate to the library find both the original PUB and the accessible converted version side by side.
Update document library default views. Consider adding a custom column to the document library that identifies conversion status: “Original PUB”, “Converted PDF” or “Converted DOCX”. Filter views can then show only converted files, making it easier for users to find accessible versions.
Keep PUB originals in an archive. Do not delete the original PUB files immediately. Move them to a dedicated archive library or archive folder rather than deleting. Now that Microsoft 365 users have lost Publisher, the PUB files no longer open in it for them, but they still contain the original data and can be converted again later if needed.
Update SharePoint search to prioritise converted files. SharePoint search indexes PDF and DOCX content for full-text search. PUB files are not indexed for content. After conversion, the content of former Publisher documents becomes searchable within SharePoint for the first time, a practical benefit beyond accessibility.
Governance and Retention Considerations
For regulated industries (finance, legal, healthcare and government), the PUB-to-PDF conversion project intersects with document retention and compliance requirements.
Retention labels apply to original PUB files. If SharePoint retention labels have been applied to PUB files under a records management or compliance policy, confirm that converting and uploading a PDF version does not conflict with the retention rules. Retention policies may prevent deletion of the original PUB during the retention period even after conversion.
Audit the conversion project itself. Document the conversion project: which files were converted, by whom, on which date and using which method. For regulated industries, this audit trail may be required to demonstrate that the converted PDF is a faithful representation of the original PUB file content.
eDiscovery and legal hold implications. If any PUB files are under legal hold or in a Microsoft Purview eDiscovery case, do not move or convert them without confirming with your legal team. Moving files to an archive or converting them during an active hold may have compliance implications.
Frequently Asked Questions
Does SharePoint have a built-in PUB to PDF conversion feature?
No. SharePoint has no built-in PUB file handler of any kind. Power Automate flows can convert some document types, but PUB is not among the supported formats. Conversion requires downloading PUB files from SharePoint, converting on Windows using either Microsoft’s PowerShell script (requires Publisher) or a batch converter (does not require Publisher) and re-uploading the converted files.
Can Microsoft Syntex or Power Platform handle PUB file conversion in SharePoint?
No. Microsoft Syntex (AI document understanding) and Power Platform (Power Automate) do not support PUB files. There is no Microsoft connector or AI model for PUB format processing. The conversion must be done outside these platforms using either Publisher’s COM interface via PowerShell or a dedicated converter tool.
What is the best approach for converting thousands of PUB files in SharePoint?
Download the files in batches using SharePoint Sync, convert in bulk using Univik PUB Converter and re-upload the converted files. For very large estates (tens of thousands of files), run the conversion in parallel across multiple Windows machines with separate file batches to reduce total processing time. Do not attempt to convert everything in a single sequential run. Distribute the workload and validate in batches rather than all at once.
What happens to SharePoint permissions when PUB files are converted and replaced?
When you upload a new PDF alongside the existing PUB in the same library, the new file inherits the library’s default permissions. If the PUB file had custom permissions (access restricted to specific users), these must be manually applied to the new PDF file, because permissions do not transfer automatically to a new file. Review custom permissions on PUB files before the conversion project and document which files need restricted access maintained after conversion.
Should PUB files in SharePoint be deleted after conversion?
Not immediately. Keep the original PUB files for at least 6 to 12 months after conversion to give users time to verify that the converted versions meet their needs. Check for any retention labels or legal holds before deletion. After the retention period, PUB files that are not under hold can be deleted to reduce SharePoint storage consumption. Archive them to cold storage or on-premise if long-term retention of the originals is required.
The Short Version
PUB files in SharePoint were already out of reach for many users, and since October 1, 2026 they no longer open in Publisher for any Microsoft 365 user. The conversion project (audit, triage, convert and re-upload) is the practical response.
Start with the audit. The inventory of PUB files across your SharePoint estate is the project plan. Once you know what you have and who owns it, the conversion method (PowerShell with Publisher or a batch converter without it) depends on your environment. Both paths get you from PUB files nobody can open to PDF and DOCX files accessible to everyone on every device.
How large is your PUB file inventory across SharePoint: dozens of files or thousands? That number determines whether a manual download-convert-upload workflow is practical or whether you need a scripted, parallelised approach.