Headings Not Showing or Linking Incorrectly #
Table of Contents (TOC) issues in Word are typically caused by incorrect heading structure rather than problems with the Table of Contents itself.

Important
Word builds the Table of Contents based on styles and document structure, not on visual formatting.
Why Table of Contents Problems Occur in Microsoft Word #
Common symptoms include entries that link to incorrect locations, entries that do not link at all, or headings that are missing from the TOC. These issues occur when the document structure does not match the visual appearance of headings.
When Word generates a TOC, it reads the underlying structure of the document. If headings are not structured correctly, the Table of Contents may include incorrect entries, omit headings, or contain broken links.
Why Are Headings Not Showing or Working Correctly in the Table of Contents in Word
Headings in Word can appear correct while not functioning as headings. This occurs when formatting is applied manually instead of using built-in heading styles.
Manually Formatted Headings
A heading may appear correct because it uses a larger font, bold formatting, or numbering. However, it may still be styled as Normal text or another non-heading style.

Warning
Headings that are manually formatted (for example using bold or font size) but not assigned a built-in heading style will not appear in the Table of Contents.
Headings with Manual Formatting Overrides
A heading may use a correct style but include additional direct formatting such as manually added numbering, modified spacing, or indentation.

Warning
Direct formatting applied to headings can override style definitions and cause incorrect hierarchy, numbering, or TOC structure.
Deleted or Broken Headings
If a heading is deleted after the Table of Contents is created, the Table of Contents may still contain a corresponding entry.

Caution
Deleting headings after the Table of Contents is created can leave broken links that point to incorrect locations or nowhere.
How Microsoft Word Builds the Table of Contents #
Word builds the Table of Contents using built-in heading styles such as Heading 1, Heading 2, and so on. It does not recognize visual formatting such as bold text, font size changes, or manually applied numbering.
Structure overrides appearance in Word. If the correct style is not applied, the heading does not function correctly in the Table of Contents.
How to Fix Table of Contents Issues in Microsoft Word #
Step 1: Apply Built-In Heading Styles
- Select the heading text.
- On the Home tab of the Ribbon, apply the correct style such as Heading 1 or Heading 2.


Best Practice
Always use built-in heading styles instead of manual formatting to ensure correct Table of Contents behavior.
Step 2: Remove Direct Formatting from Headings
Remove manually applied numbering, spacing, indentation, and other direct formatting.
- Select the heading text.
- Remove manually added numbering.
- Remove any direct formatting.
- Check that the heading still uses the correct built-in heading style.

Important
Ensure that formatting is controlled by the style definition. This prevents conflicts between visual formatting and structural formatting.
Step 3: Modify Styles Instead of Formatting Text
- Right-click the style such as Heading 1.
- Select Modify.
- Adjust formatting in the dialog box.


Best Practice
Modifying styles ensures that formatting changes are applied consistently across the document.
Step 4: Update the Table of Contents
- Click inside the Table of Contents.
- Select Update Table.
- Select Update entire table.

The Table of Contents updates based on the corrected heading structure and reflects the intended hierarchy.

Note
The Table of Contents does not update automatically after structural changes. It must be updated manually.
Real-Life Challenges with Heading Structures #
Documents often contain content from multiple authors, copied sections from other files, and mixed templates. This results in inconsistent heading structures and hidden formatting issues.
Correcting headings individually can be time-consuming and may introduce additional inconsistencies.
How to Automate Heading and Table of Contents Corrections Using OnStyle #
The OnStyle Word Add-in provides tools to detect and correct heading-related issues automatically.
OnStyle can detect heading numbering issues, incorrect list formatting, headings that are out of sequence, broken internal hyperlinks, and direct formatting applied to headings.

This enables faster identification and correction of structural issues compared to manual review.
How to Fix Heading Structure in Word #
The OnStyle Word add-in can remove direct formatting from headings, apply correct styles to manually formatted text, remove manually added numbering, and normalize heading structure across the document.

Once the structure is corrected, the Table of Contents updates automatically.
Why Structure Is More Important Than Formatting in Word #
A key principle in Word formatting is that structure overrides appearance. A heading functions correctly only when the correct style is applied and the hierarchy is consistent.
Maintaining proper structure ensures accurate Table of Contents entries, correct navigation, and consistent document formatting.
Summary #
Table of Contents issues in Microsoft Word are typically caused by incorrect heading structure. Using built-in heading styles, removing direct formatting, and maintaining a consistent structure ensures correct Table of Contents behavior. In complex documents, automation tools like OnStyle can support detection and correction of structural issues, improving consistency and document quality control.
