Formatting Issues

Fix Duplicate Em Dash and En Dash Characters in Microsoft Office

Maira Mehtab Sep 27, 2026 870 views

Question details

Using the numeric Alt codes (Alt+0151 or Alt+0150) to insert em dashes or en dashes results in duplicate characters appearing in the document.

Product: Microsoft 365 (Word, PowerPoint, Excel)
Device & OS: not provided
Scenario: Typing em dashes and en dashes using Alt codes while editing documents, spreadsheets, or presentations.
Observed behavior: The application incorrectly inserts two dash characters instead of a single dash when the Alt code shortcut is used.

Before you start

Ensure your Num Lock is turned on when using Alt codes, and try typing the same codes in a plain text editor like Notepad to confirm whether the duplication is an Office-specific glitch or a keyboard hardware issue.

Solution 1Recommended

Create Custom Keyboard Shortcuts for Dashes

Bypass the faulty Alt codes by assigning new custom keyboard shortcuts directly within the Office application for seamless insertion.

Since the native Alt codes are misregistering in certain Microsoft 365 builds, creating a custom shortcut mapped directly to the special character completely bypasses the bug.

Open Special Characters

In your Microsoft Word document, navigate to the 'Insert' tab on the top ribbon, click on 'Symbol', and select 'More Symbols' from the dropdown menu.

Select the Dash Symbol

Switch to the 'Special Characters' tab. Highlight the 'Em Dash' or 'En Dash' from the list provided.

Assign Custom Shortcut

Click the 'Shortcut Key' button. In the 'Press new shortcut key' box, press a combination like 'Ctrl+Shift+M' (for Em Dash) or 'Ctrl+Shift+N' (for En Dash), then click 'Assign'.

Shortcut Saved: Your new shortcuts are saved to the Normal template and will be available in all future Word documents.

Solution 2

Use Standard Built-in Word Shortcuts

Use the default keyboard shortcuts provided by Microsoft Word instead of the numeric Alt codes.

Solution 3

Vote on the Microsoft Feedback Portal

Report and upvote the issue in the Microsoft Feedback portal to help expedite an official software patch.

Free Microsoft Office alternative

Avoid Persistent Formatting Bugs with WPS Office

If you are tired of encountering formatting bugs like the duplicate dash issue in Microsoft 365, consider switching to WPS Office. WPS Office correctly handles standard Alt codes for all special characters without duplication, offering a smooth, reliable writing experience.

1. Download WPS Office: Visit the official WPS website to download the free installation package for your operating system.
2. Install the Software: Run the installer and follow the simple on-screen instructions to set up WPS Office on your device.
3. Open Your Documents: Launch WPS Writer and open your existing Office files to continue working seamlessly without character duplication bugs.

Flawless handling of Alt codes and special character formatting100% compatible with Microsoft Word, Excel, and PowerPoint formatsLightweight installation that runs smoothly on older and newer devicesFamiliar ribbon interface for a seamless transition with zero learning curve

microsoft office alternative - wps office

Frequently Asked Questions

Why do Alt+0151 and Alt+0150 produce duplicate dashes in Office?

This is a known software bug in certain recent versions of Microsoft 365 where the application incorrectly registers the Alt code input twice, outputting two characters instead of one. Microsoft developers are tracking the issue via the Feedback Portal.

Can I use AutoFormat to insert an em dash without Alt codes?

Yes. In Microsoft Word, you can type two standard hyphens (--) between two words without spaces. When you press the spacebar after the second word, the AutoFormat feature will automatically convert the hyphens into an em dash.

Can I fix this issue using the Insert Symbol menu?

Yes, manually inserting dashes via the 'Insert' > 'Symbol' > 'More Symbols' menu avoids the duplication bug entirely, as the issue is specifically tied to keyboard Alt code processing.

Document & File Issues