For Microsoft 365 subscribers: Publisher stops working entirely on October 13, 2026. PUB files cannot be opened after that date the application is removed. For perpetual licence users (Office 2021, standalone Publisher): the application keeps running after October 2026 but receives no security updates. In both cases, PUB files you have not converted before losing Publisher access become permanently inaccessible. The PUB format is proprietary no other application reads it reliably. Convert before the deadline using Publisher’s built-in Save As for small numbers of files or Univik PUB Converter for bulk conversion.
The Short Answer
Your PUB files do not disappear. The files themselves sit on your drive exactly where they were. What disappears is the ability to open them.
PUB is a proprietary format tied to Microsoft Publisher. Nothing other than Publisher reads it reliably. When Publisher stops being available or stops being supported your PUB files become locked. You can see them. You cannot open them.
What exactly happens depends on which version of Publisher you use.
If You Use Microsoft 365
October 13, 2026 is a hard stop.
On that date, Microsoft removes Publisher from the Microsoft 365 suite entirely. The application will not launch. You cannot open a PUB file in Publisher because Publisher no longer exists in your installation. You cannot edit PUB files. You cannot export them from Publisher to PDF or Word because Publisher is not there to do the exporting.
Any PUB file you have not converted before that date is inaccessible. Not difficult to access. Inaccessible. You would need to find a machine that still has Publisher installed a perpetual licence user and ask them to open and convert the file for you.
Not sure if you are on Microsoft 365?
Open Publisher. Go to File then Account. If the product name says “Microsoft 365” or “Office 365,” you are on a subscription and the October 13 kill switch applies to you. If it says “Publisher 2021,” “Publisher 2019” or similar, you have a perpetual licence different situation covered below.
If You Have a Perpetual Licence
If you own Office 2021, Office 2019 or a standalone Publisher licence, the application keeps working after October 2026. You can still open PUB files. You can still edit them.
What changes is support.
No more security patches. Microsoft stops issuing security updates for Publisher after October 1, 2026. A malformed PUB file from an untrusted source could exploit an unpatched vulnerability. The risk grows over time as Windows continues to receive updates that Publisher no longer gets to match.
No technical support. Microsoft will not assist with Publisher problems after this date.
Windows updates may break it. A Windows security update could change a system component Publisher depends on. Since Publisher is no longer maintained, these breaks will not be fixed. Publisher could stop working without warning after any Windows update.
Upgrading Office removes Publisher. Office 2024 does not include Publisher. If you upgrade your Office installation, Publisher goes with the old version. You cannot keep Publisher and upgrade Office simultaneously.
The perpetual licence buys time, not a permanent solution. Converting your important PUB files now while Publisher is still fully supported and reliable is a better use of that time than relying on an ageing, unsupported installation.
Why PUB Files Cannot Be Opened by Anything Else
This is the part that catches people off guard.
Microsoft never published a specification for the PUB file format. DOCX is an ISO open standard any developer can read the specification and build software that opens Word documents, which is why LibreOffice, Google Docs and dozens of other tools handle DOCX reliably. PUB has no equivalent open specification. It is a proprietary binary format that Microsoft documented internally but never released publicly.
The consequence: no third-party application has been able to implement reliable PUB reading. LibreOffice Draw has partial PUB support that handles only basic files. Anything with complex layouts, custom fonts, layered elements or master pages tends to fail or produce a broken result. There is no free, reliable, widely available tool that opens PUB files other than Publisher itself.
When Publisher is gone, PUB files without conversion become what engineers call digital fossils files that exist but cannot be accessed with any current tool. The content is technically still there, inside the binary file. You just cannot get to it.
Three Paths Forward
Convert Before the Deadline
The recommended path. Use Publisher while it is still working to convert your PUB files to PDF (for archiving and printing) and DOCX (for files you may want to edit later). For large archives, use a batch converter. This is the only path that preserves access to your content regardless of what happens to Publisher.
Keep a Perpetual Licence Running
If you have Office 2021 with Publisher, you can keep using it after October 2026. The application keeps working. This is a reasonable bridge if you have many files to convert and need more time but the clock is still ticking on the security risks and any Office upgrade removes Publisher permanently.
Rebuild in a New Tool
For ongoing content newsletters, brochures, flyers you create regularly the existing PUB templates need to be rebuilt in a replacement tool. Convert the existing archive to PDF for reference, then rebuild active templates in Canva, Word or Affinity Publisher. New content is created in the new tool going forward.
How to Check Which Version You Have
Open Publisher. Go to File in the menu bar then Account.
| What You See | Your Situation | What Happens in October 2026 |
|---|---|---|
| “Microsoft 365” or “Office 365” in the product name | Microsoft 365 subscription | Publisher removed entirely on October 13. PUB files inaccessible without conversion. |
| “Publisher 2021” or “Office 2021” | Perpetual licence most affected | App keeps running but loses security support October 1, 2026. No Microsoft fixes after that date. |
| “Publisher 2019” or “Office 2019” | Perpetual licence already out of mainstream support | Publisher keeps running but has been out of mainstream support since October 2023. Higher risk. |
| “Publisher 2016” or older | Perpetual licence long past end of support | App may keep running but is significantly out of date. Conversion is urgent. |
How to Convert PUB Files Before the Deadline
The conversion method depends on how many files you have.
Small number of files (under 20): Open each PUB file in Publisher. Go to File then Save As. Choose PDF to preserve the layout exactly or Word Document to keep the content editable. This is free and uses Publisher’s own rendering engine the most accurate conversion available while Publisher is still working.
Larger archive (20 to hundreds of files): Manual conversion is not practical. Univik PUB Converter converts PUB files to PDF, Word and other formats in bulk on Windows. It works without Publisher installed which is useful for converting files after Publisher access has already been lost or for machines that never had Publisher. Load the files, select the output format and run the batch.
Finding all your PUB files: Before converting, find everything. Open Windows Explorer and search for *.pub to locate files on your local drive. For network drives or SharePoint, your IT team can run a search across shared storage. Microsoft’s own documentation suggests a PowerShell command for bulk discovery: Get-ChildItem -Path C:\ -Recurse -Filter *.pub
Which format to convert to
Convert to PDF for any file you only need to view, print or distribute PDF preserves the layout exactly and is readable on any device forever. Convert to DOCX for any file whose content you may need to edit in future Word format makes the text accessible but the layout will shift somewhat. When in doubt, convert to both and keep both. Storage is cheap. Losing access to the content is not recoverable. For more detail on the DOCX path see our PUB to Word conversion guide.
Frequently Asked Questions
Do PUB files get deleted when Publisher is retired?
No. The files themselves are not deleted. They remain exactly where they are on your drive. What changes is your ability to open them the application that reads PUB files is removed (for M365 users) or becomes unsupported (for perpetual licence users). The distinction matters: your files are safe, but they become inaccessible without the application that can open them.
Can I open PUB files in Word, PowerPoint or any other Microsoft 365 app?
No. None of the Microsoft 365 applications can open PUB files. Word, PowerPoint, Excel, OneNote and the rest all use their own formats. PUB is specific to Publisher. After Publisher is removed from Microsoft 365 in October 2026, there is no Microsoft 365 application that opens PUB files.
What happens if I try to open a PUB file after October 2026 on a Microsoft 365 subscription?
Windows will not know which application to use to open the file. It may prompt you to choose an application or search the Microsoft Store for something that can open it. No application in the Microsoft Store natively opens PUB files reliably. The file will effectively be unreadable without a third-party converter or access to a machine with a perpetual Publisher installation.
Are there any online tools that can open PUB files after October 2026?
A small number of online converters claim PUB file support. Results are inconsistent they handle basic PUB files reasonably but fail on files with complex layouts, custom fonts, layered images or master page elements. The reliable conversion window is now, while Publisher is still available to use for conversion. Do not count on third-party tools to handle your archive after the deadline.
I have thousands of PUB files. How do I convert them all?
You need a batch converter. Microsoft provides a PowerShell script that uses Publisher’s COM interface to batch-convert PUB files to PDF but it requires Publisher to be installed and running. For machines that no longer have Publisher or for a more reliable batch workflow, Univik PUB Converter handles bulk PUB-to-PDF and PUB-to-Word conversion on Windows without requiring Publisher to be installed. Start the conversion project now do not wait until the deadline is imminent.
Will Microsoft release a tool to convert PUB files after Publisher is retired?
Microsoft has not announced any such tool. Their guidance is to convert files before the October 2026 deadline using Publisher itself. After that date, Microsoft’s recommended path for accessing content from PUB files is Word’s ability to open PDFs for editing which means the workflow is: convert PUB to PDF (before the deadline), then open PDF in Word (after the deadline) if editing is needed. This is a two-step workaround, not a clean solution.
Conclusion
PUB files do not disappear in October 2026. Your access to them does at least for Microsoft 365 users and eventually for perpetual licence users as unsupported software ages and breaks.
The answer is the same regardless of which scenario you are in: convert the files you care about before Publisher is gone. PDF for anything you need to preserve as-is. DOCX for anything you might want to edit. Now, while Publisher still works reliably.
For the full picture of what happens to Publisher across all licence types, the timeline and an action checklist, see our complete Microsoft Publisher end of life guide. For help choosing a replacement tool for creating new content going forward, see our Publisher alternatives guide.
How many PUB files are you dealing with? The answer to that question a handful or hundreds determines whether a manual or batch conversion approach makes more sense for you.