Microsoft 365 (and Office 365) subscribers get more frequent software updates than those who have purchased Office without a subscription, which means subscribers have access to the latest features, security patches, and bug fixes. But it can be hard to keep track of the changes in each update and know when they’re available. We’re doing this for you, so you don’t have to.

Following are summaries of the updates to Microsoft 365/Office 365 for Windows over the past year, with the latest releases shown first. We’ll add info about new updates as they’re rolled out.

Note: This story covers updates released to the Current Channel for Microsoft 365/Office 365 subscriptions. If you’re a member of Microsoft’s Office Insider preview program or want to get a sneak peek at upcoming features, see the Microsoft 365 Insider blog.

Version 2605 (Build 20026.20140)

Release date: June 3, 2026

This build fixes a single bug, in which images didn’t display when using top and bottom text wrapping in classic Outlook.

Get more info about Version 2605 (Build 20026.20140).

Version 2605 (Build 20026.20112)

Release date: May 26, 2026

This build offers “various fixes to functionality and performance,” according to Microsoft.

Get more info about Version 2605 (Build 20026.20112).

Version 2605 (Build 20026.20076)

Release date: May 20, 2026

This build fixes several bugs, including one in which Excel or PowerPoint closed unexpectedly in rare cases while the user was actively co-authoring, particularly when opening a document for the first time.

Get more info about Version 2605 (Build 20026.20076).

Version 2604 (Build 19929.20172)

Release date: May 14, 2026

This build fixes a bug in Outlook in which sending mail failed when multiple Exchange accounts were configured.

Get more info about Version 2604 (Build 19929.20172).

Version 2604 (Build 19929.20164)

Release date: May 12, 2026

The build plugs a number of security holes. For details, see Release notes for Microsoft Office security updates.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2604 (Build 19929.20164).

Version 2604 (Build 19929.20136)

Release date: May 5, 2026

This build fixes a bug in which Outlook closed unexpectedly after replying to a mail item with labels.

Get more info about  Version 2604 (Build 19929.20136).

Version 2604 (Build 19929.20106)

Release date: April 29, 2026

This build includes “various fixes to functionality and performance,” according to Microsoft.

Get more info about Version 2604 (Build 19929.20106).

Version 2604 (Build 19929.20090)

Release date: April 21, 2026

This build includes “various fixes to functionality and performance,” according to Microsoft.

Get more info about Version 2604 (Build 19929.20090).

Version 2603 (Build 19822.20182)

Release date: April 14, 2026

In this build, Copilot can now edit your PowerPoint documents. Copilot can start a new presentation or build on an existing one, generate slides, update content, improve layouts, and polish design, while preserving formatting, structure, and branding. 

The build also plugs a number of security holes. For details, see Release notes for Microsoft Office security updates.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2603 (Build 19822.20182).

Version 2603 (Build 19822.20168)

Release date: April 9, 2026

This build fixes several bugs, including one in Outlook in which users could not close the Copilot chat pane using a keyboard. Users can now close the pane by navigating to the Close button using a keyboard or by using the assigned keyboard shortcut.

Get more info about Version 2603 (Build 19822.20168).

Version 2603 (Build 19822.20142)

Release date: March 31, 2026

This build includes “various fixes to functionality and performance,” according to Microsoft.

Get more info about Version 2603 (Build 19822.20142).

Version 2603 (Build 19822.20114)

Release date: March 24, 2026

This build fixes a single bug in which PowerPoint sometimes closed unexpectedly when opening a newly created empty file from the OneDrive folder.

Get more info about Version 2603 (Build 19822.20114).

Version 2602 (Build 19725.20190)

Release date: March 18, 2026

This build fixes an Outlook bug in which updating a single instance of a recurring meeting in a Microsoft 365 group calendar updated the entire series.

Get more info about Version 2602 (Build 19725.20190).

Version 2602 (Build 19725.20172)

Release date: March 10, 2026

This build introduces agent mode in Word, which adds a conversational chat experience that helps create, edit, and refine document content as you work. In addition, the build fixes a bug that impacted the rendering of extended characters in calendar items, causing certain characters to appear as question marks.

The build also plugs a number of security holes. For details, see Release notes for Microsoft Office security updates.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2602 (Build 19725.20172).

Version 2602 (Build 19725.20152)

Release date: March 3, 2026

This build fixes a bug in which closing a document sometimes remained in progress indefinitely after the Office app resumed from sleep or hibernation.

Get more info about Version 2602 (Build 19725.20152).

Version 2602 (Build 19725.20126)

Release date: February 24, 2025

This build fixes several bugs, including one that caused OneNote to close unexpectedly upon startup.

Get more info about Version 2602 (Build 19725.20126).

Version 2601 (Build 19628.20214)

Release date: February 17, 2025

This build includes, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2601 (Build 19628.20214).

Version 2601 (Build 19628.20204)

Release date: February 10, 2026

This build fixes a bug that sometimes prevented users from opening emails with the Encrypt Only label in Outlook.

It also plugs a number of security holes. For details, see Release notes for Microsoft Office security updates.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2601 (Build 19628.20204).

Version 2601 (Build 19628.20166)

Release date: February 3, 2026

This build includes, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2601 (Build 19628.20166).

Version 2601 (Build 19628.20150)

Release date: January 27, 2025

In this build, OneNote applies your chosen proofing language more consistently, so you don’t have to reset it for every paragraph when writing in multiple languages. In addition, the build fixes several bugs, including one that caused Office applications to become unresponsive when profile card-related activities were performed.

Get more info about Version 2601 (Build 19628.20150).

Version 2512 (Build 19530.20184)

Release date: January 21, 2025

This build includes, in Microsoft’s words, “Various fixes to functionality and performance.”

Get more info about Version 2512 (Build 19530.20184).

Version 2512 (Build 19530.20144)

Release date: January 13, 2026

This build fixes a number of bugs, including one that caused Excel, PowerPoint, and Word to become unresponsive when profile card-related activities were performed.

It also plugs a number of security holes. For details, see Release notes for Microsoft Office security updates.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2512 (Build 19530.20144).

Version 2512 (Build 19530.20138)

Release date: January 8, 2025

This build offers, in Microsoft’s words, “Various fixes to functionality and performance.”

Get more info about Version 2512 (Build 19530.20138).

Version 2511 (Build 19426.20218)

Release date: December 16, 2025

This build offers, in Microsoft’s words, “Various fixes to functionality and performance.”

Get more info about Version 2511 (Build 19426.20218).

Version 2511 (Build 19426.20186)

Release date: December 9, 2025

This Patch Tuesday build offers, in Microsoft’s words, “Various fixes to functionality and performance.” The build also has a variety of security updates (see details).

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2511 (Build 19426.20186).

Version 2511 (Build 19426.20170)

Release date: December 3, 2025

This build includes, in Microsoft’s words, “Various fixes to functionality and performance.”

Get more info about Version 2511 (Build 19426.20170).

Version 2510 (Build 19328.20244)

Release date: November 20, 2025

This build fixes a bug in Outlook that caused users to see “Contacting the server for information” repeatedly when loading some emails.

Get more info about Version 2510 (Build 19328.20244).

Version 2510 (Build 19328.20232)

Release date: November 18, 2025

This build includes, in the words of Microsoft, “various fixes to functionality and performance.”

Get more info about Version 2510 (Build 19328.20232).

Version 2510 (Build 19328.20190)

Release date: November 11, 2025

This Patch Tuesday build fixes a bug in Outlook that caused some recipients to be unable to access OneDrive links shared with them via email. The build also has a variety of security updates (see details).

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2510 (Build 19328.20190).

Version 2510 (Build 19328.20178)

Release date: November 4, 2025

This build fixes a single bug, in which @mention searches produced no results in Office apps.

Get more info about Version 2510 (Build 19328.20178).

Version 2510 (Build 19328.20158)

Release date: October 30, 2025

This build introduces a new Get Data dialog in Windows that simplifies finding and using external data, and adds Analyze Data to the Data tab.

The build also fixed an bug in Outlook that prevented users from downloading web add-ins in some virtualized environments.

Get more info about Version 2510 (Build 19328.20158).

Version 2509 (Build 19231.20216)

Release date: October 21, 2025

This build has, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2509 (Build 19231.20216).

Version 2509 (Build 19231.20194)

Release date: October 14, 2025

This build has a variety of security updates (see details), along with various fixes to functionality and performance.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2509 (Build 19231.20194).

Version 2509 (Build 19231.20172)

Release date: October 7, 2025

This build has, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2509 (Build 19231.20172).

Version 2509 (Build 19231.20156)

Release date: October 1, 2025

This build fixes two bugs, one in Excel in which ribbon controls were not rendered when rejoining Office sessions in a virtual machine, Azure Virtual Desktop, or remote desktop environment, and another that caused Outlook to terminate unexpectedly when starting.

Get more info about Version 2509 (Build 19231.20156).

Version 2508 (Build 19127.20264)

Release date: September 23, 2025

This build has, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2508 (Build 19127.20264).

Version 2508 (Build 19127.20240)

Release date: September 16, 2025

This build has, in Microsoft’s words, “various fixes to functionality and performance.”

Get more info about Version 2508 (Build 19127.20240).

Version 2508 (Build 19127.20222)

Release date: September 9, 2025

This build has multiple security updates (see details), along with various fixes to functionality and performance.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2508 (Build 19127.20222).

Version 2508 (Build 19127.20192)

Release date: September 3, 2025

This build fixes a bug in which some Outlook add-ins were getting “Office.auth.getAccessToken is not a function” errors.

Get more info about Version 2508 (Build 19127.20192).

Version 2508 (Build 19127.20154)

Release date: August 26, 2025

This build fixes a bug that caused Outlook to terminate unexpectedly when sending a meeting invite with an encryption label. It also adds support for pixelated rendering of embedded images in SVG assets for the entire Office suite.

Get more info about Version 2508 (Build 19127.20154).

Version 2507 (Build 19029.20208)

Release date: August 19, 2025

This build fixes a variety of bugs.

Get more info about Version 2507 (Build 19029.20208).

Version 2507 (Build 19029.20184)

Release date: August 12, 2025

This build fixes a bug which required users to restart Outlook to open a .msg file after initially accessing it once. The build also includes a variety of security updates (see details).

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2507 (Build 19029.20184).

Version 2507 (Build 19029.20156)

Release date: August 5, 2025

This build fixes a single bug, in which users had to restart Outlook to open a .msg file after initially accessing it once.

Get more info about Version 2507 (Build 19029.20156).

Version 2507 (Build 19029.20136)

Release date: July 30, 2025

This build fixes a wide variety of bugs, including in which Outlook closed unexpectedly shortly after launch, and another in Word in which the word count sometimes displayed incorrectly.

Get more info about Version 2507 (Build 19029.20136).

Version 2506 (Build 18925.20184)

Release date: July 22, 2025

This build fixes two bugs, one that caused the Copilot Command Center to continue to be visible after disabling the Copilot user interface, and another in which when creating handouts in PowerPoint, certain characters (full-width numbers) couldn’t be properly transferred to the handout.

Get more info about Version 2506 (Build 18925.20184).

Version 2506 (Build 18925.20168)

Release date: July 15, 2025

This build fixes two bugs, one that caused Visio 32-bit to close unexpectedly when using the Drawing control, particularly in setups involving COM components or .NET integrations, and another in Word in which copying and pasting content between documents sometimes changed the applied style unexpectedly.

Get more info about Version 2506 (Build 18925.20168).

Version 2506 (Build 18925.20158)

Release date: July 8, 2025

This Patch Tuesday build fixes several bugs in Outlook, PowerPoint, Word, and the whole Office suite, including one that caused the Copilot icon to unexpectedly display in Outlook when Copilot had been disabled by the admin in government cloud.

The release also includes a variety of security updates (see details).

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2506 (Build 18925.20158).

Version 2506 (Build 18827.20176)

Release date: July 1, 2025

This build fixes a wide variety of bugs, including one in Word in which print preview sometimes stopped working when printing long emails.

Get more info about Version 2506 (Build 18827.20176).

Version 2505 (Build 18827.20176)

Release date: June 26, 2025

This build introduces several new features, including one in Excel in which the PivotTables dialog box interface has been replaced by a redesigned panel, making it easier to view all of your options and simpler to change your data selection before inserting a recommended PivotTable.

Get more info about Version 2505 (Build 18827.20176).

Version 2505 (Build 18827.20164)

Release date: June 17, 2025

This build fixes a bug that caused the “Try the new Outlook” toggle to be enabled when working in Classic Outlook side by side with the new Outlook.

Get more info about Version 2505 (Build 18827.20164).

Version 2505 (Build 18827.20150)

Release date: June 10, 2025

This build fixes several bugs, including one for the entire Office suite in which a Save As attempt on an existing file didn’t complete successfully, and subsequent attempts continued to encounter issues when trying to save to a file that no longer existed.

This Patch Tuesday release also includes a variety of security updates: see details.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about  Version 2505 (Build 18827.20150).

Version 2505 (Build 18827.20140)

Release date: June 3, 2025

This build offers a variety of bug and performance fixes.

Read about Version 2505 (Build 18827.20140).

Version 2504 (Build 18730.20186)

Release date: May 20, 2025

This build introduces a new PowerPoint feature: Notification emails for mentions, tasks, comments, and replies will now contain context previews even when the source document is encrypted, and the email will inherit the document’s security policies.

Get more info about Version 2504 (Build 18730.20186).

Version 2504 (Build 18730.20168)

Release date: May 13, 2025

This build fixes a bug in which users were seeing high CPU usage when typing in Outlook. It also includes a variety of security updates: see details.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2504 (Build 18730.20168).

Version 2504 (Build 18730.20142)

Release date: May 6, 2025

This build includes various bug and performance fixes.

Get more info about Version 2504 (Build 18730.20142).

Version 2504 (Build 18730.20122)

Release date: April 29, 2025

This build fixes a wide variety of bugs, including one in which PowerPoint was unable to open a file from a network mapped drive from File Explore, another in which Word closed unexpectedly when opening .doc files, and another for the entire Office suite in which large 3D files couldn’t be inserted.

Get more info about Version 2504 (Build 18730.20122).

Version 2503 (Build 18623.20208)

Release date: April 17, 2025

This build fixes a bug that could cause Excel to stop responding.

Get more info about Version 2503 (Build 18623.20208).

Version 2503 (Build 18623.20178)

Release date: April 8, 2025

This build fixes a single bug in Word in which users may have encountered an issue with saving, seeing the message “saving…” in the title bar. It  also includes a variety of security updates. Go here for details.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2503 (Build 18623.20178).

Version 2503 (Build 18623.20156)

Release date: April 2, 2025

This build lets you use Dark Mode in Excel, which darkens your entire sheet, including cells, and may reduce eye strain. It also fixes several bugs, including one in Word in which opening specific files that contain many tracked changes and comments resulted in poor performance, and one in PowerPoint in which the app was not displaying the icon for an inserted PDF object.

Get more info about Version 2503 (Build 18623.20156).

Version 2502 (Build 18526.20168)

Release date: March 11, 2025

This build fixes several bugs, including one in which some Word files with numerous tracked changes and comments were slow. It also includes a variety of security updates: see details.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2502 (Build 18526.20168).

Version 2502 (Build 18526.20144)

Release date: March 5, 2025

This build fixes a wide variety of bugs, including one in Word in which the default font size may not be 12pt as expected, and another in which PowerPoint automatically closed when the system went into hibernate or sleep mode.

Get more info about Version 2502 (Build 18526.20144).

Version 2501 (Build 18429.20158)

Release date: February 11, 2025

This build removes the option to display Track Changes balloons in left margin in Word. It also includes a variety of security updates. See “Release notes for Microsoft Office security updates” for details.

What IT needs to know: Because this is a security update, it should be applied relatively soon. Over the next few weeks, check for reports about problematic issues, and if all seems well, apply the update.

Get more info about Version 2501 (Build 18429.20158).