How to Add a Header Underline in Word for Every Page

To add a line beneath a header in Microsoft Word, open the header, click its paragraph, then choose Home > Paragraph > Borders > Bottom Border. The border is usually the simplest way to create a neat underline that repeats with the header. You can adjust its color, weight, and position, and use a line shape instead if you need more control over its length or placement.

What You’ll Need

A Word document and permission to edit it.
A header area to format. If the document does not have one yet, Word can create it as you begin editing the header.
For the steps below, Microsoft Word for Microsoft 365 on Windows. The Mac ribbon has similar commands; differences are noted where useful.

You do not need to select the entire header text or install an add-in. A header underline is typically a paragraph border, not an underline applied to the letters. That distinction matters: a paragraph border can stretch across the header area, while text underlining follows the characters.

Step-by-Step

Open the header. Double-click near the top margin of a page. Alternatively, use Insert > Header > Edit Header. Word opens the header editing area and displays the Header & Footer tab. If the document has no header, choose a basic layout or select Edit Header to start with a blank header area. On a Mac, you can also double-click the top of the page or use Insert > Header.
Find the paragraph that should sit above the line. Click inside the header text you want the line to follow. If the header has a logo and text, put the cursor in the paragraph that should carry the border, often the last line of header text. A bottom border belongs to a paragraph, so it does not automatically underline every separate item in a header. If the header contains several paragraphs, click the final paragraph to place one line beneath the complete block.
Apply a bottom border. Select the Home tab, find the Paragraph group, and open the Borders drop-down arrow. Choose Bottom Border. In Word for Microsoft 365 on Windows, the Borders control is in Home > Paragraph; the icon may look like a small square or grid. On a Mac, use Home > Paragraph > Borders and select Bottom Border. The line should appear beneath the paragraph in the header. Clicking the main Borders button may repeat its last command, so use the arrow when you need to choose a specific edge.
Check the line across the page. A paragraph border usually runs across the paragraph width, between the page margins, rather than stopping at the last letter. If your header paragraph has a left or right indent, the line may start or end inside the margins. If the line is too short or offset, remove unnecessary paragraph indents: click in the paragraph and use Home > Paragraph dialog launcher to inspect the Indentation settings, then set Left and Right to 0. You can also adjust the paragraph with the ruler, if it is displayed.
Change the border style if needed. Open the Borders drop-down again and choose Borders and Shading. In the dialog, select the Borders tab, choose Custom under Setting, then use the preview to turn on only the bottom edge. Choose a line style, color, and width that suit the document. Confirm that Apply to is set to Paragraph, then select OK. The dialog layout can vary slightly between Word builds; look for the preview and the Apply to control. Avoid selecting a box border unless you want lines on the other sides of the paragraph too.
Review header spacing. If the line looks crowded against the words, add space after the header paragraph rather than inserting repeated blank lines. Open the Paragraph dialog from Home > Paragraph, then increase Spacing After by a small amount. To move the line itself farther from the text, you can adjust the paragraph’s spacing or the border distance in Borders and Shading, if that control is available in your Word version. Make small changes and check the page layout after each one.
Check whether the document uses different headers. With the header open, inspect the Header & Footer tab for Different First Page or Different Odd & Even Pages. If either option is on, Word may have separate header content for the first page or for odd and even pages. Add the border to each header type where you want it. In a document with section breaks, check each section as well; if Link to Previous is off, that section’s header can be formatted independently.
Close the header and inspect more than one page. Select Close Header and Footer on the ribbon, or double-click in the main document body. Check a page near the beginning and another later in the document. Confirm that the rule is visible, that it does not overlap text, and that it appears on the intended pages. Save the document once the result looks right.

Alternative: draw a line shape. Use this when you need a line that is shorter than the text area or positioned independently. While editing the header, choose Insert > Shapes > Line, then drag across the header. Hold Shift while dragging to keep the line horizontal. Use Shape Format to change its outline color and weight. A shape can be harder to keep aligned when margins or header content change, so a paragraph border is usually more dependable for a standard divider. If the shape does not appear on every page, check that it was inserted into the repeating header rather than the document body.

Common Mistakes

Using text underline instead of a paragraph border. Ctrl+U on Windows (Command+U on Mac) underlines selected characters. It does not create a full-width divider. For a rule beneath the header paragraph, use the Borders drop-down and Bottom Border.
Choosing the wrong border edge. Top Border, Left Border, or Outside Borders will not create the same single rule beneath the header. If you see an unwanted box, reopen Borders and Shading, turn off the extra edges in the preview, and leave only the bottom edge selected.
Applying the border to the wrong paragraph. The line follows the paragraph where the cursor is placed. If the header has a title on one line and a date on another, putting the border on the first line can make the divider appear between them. Click in the last paragraph above the intended divider.
Forgetting separate first-page or section headers. A line on the first page does not prove that every header is formatted. Different First Page, odd/even headers, and unlinked sections can all produce separate header versions.
Adding repeated hyphens or underscores. Typed characters may wrap, print unevenly, or shift when the font changes. A border or line shape is a more stable way to create a divider.

Tips

Keep the line visually quiet. A thin black or gray rule generally separates the header without competing with the page content. Use a heavier line only when it fits the rest of the document’s design.
Use one consistent approach throughout. If sections share the same header, keep the same border style and spacing. Consistency makes the document look intentional, especially in reports, proposals, and manuals.
Use borders for a line that should track the text area. Paragraph borders respond naturally to the paragraph and margin layout. Use a shape if you need a deliberately shorter rule or a position that does not depend on the paragraph width.
Inspect print layout, not just the editing view. The header area can look different when Word displays formatting marks or when you view a page at a different zoom. Use View > Print Layout and, if the document will be printed, check Print Preview before sharing it.
Keep an untouched copy when changing a complex template. If the file has several sections, logos, or different headers, save a copy before making broad changes. It is easier to compare the original if a border or spacing adjustment affects more pages than expected.

Troubleshooting

The line does not appear. Confirm that the cursor is in the header paragraph, not in the page body, and that you chose Bottom Border from the Borders menu. If the paragraph is empty, click in it and type the header text or add a nonprinting paragraph mark if appropriate; an empty paragraph can be difficult to locate. Reopen Borders and Shading and check that the bottom edge is enabled, the line color is not white, and the width is not set so faintly that it disappears on screen.

The border appears under only one page. First check whether Different First Page or Different Odd & Even Pages is enabled. Then look for section breaks and inspect the header in each section. If a section is not linked to the previous one, format that header separately. If it is linked, changes to the shared header may also change earlier sections, so check the document before editing.

The line is too short, too long, or misaligned. For a paragraph border, check the paragraph’s left and right indents and the page margins. Also verify whether the header text sits in a table cell; a border applied inside a cell may follow the cell width rather than the full page width. For a shape, select it in the header and adjust its endpoints or use Shape Format positioning options. When the shape is difficult to select, click near the line while the header is open, or use the Selection Pane if available.

The line sits too close to the text or looks too heavy. Change the paragraph spacing or the border settings rather than adding multiple blank paragraphs. In Borders and Shading, select a lighter color or smaller width. If you cannot see the change in the editing view, zoom in and check Print Preview; very thin rules can be subtle at low zoom.

The line vanishes in a PDF or printout. Check that the border uses a printable color and is not placed at the extreme page edge. Export again with File > Save As or File > Export, depending on your Word version, and inspect the resulting PDF. If the line is still missing, verify that it is part of the header and not a drawing object hidden behind another element.

Frequently Asked Questions

Will the header underline appear on every page?
Usually, yes: a border in a repeating header appears wherever that header is used. It may not show on a first page, odd or even page, or section with a different or unlinked header. Check those variations in the Header & Footer tab.

Can I underline only the header words?
Yes. Select the words and use Ctrl+U on Windows or Command+U on Mac. That creates an underline beneath the text itself, not a divider spanning the paragraph. For a full-width rule, use Bottom Border instead.

Can I change the color and thickness?
Yes. Open Borders and Shading from the Borders drop-down, select the bottom edge in the preview, and choose a line color and width before applying the change to the paragraph. Available line styles may differ slightly by Word version.

Can I add a header underline in Word for the web?
Word for the web offers common header editing and paragraph formatting, but some detailed border controls may be limited or arranged differently from the Windows desktop app. If you cannot find the border options, open the document in the desktop version of Word and use Home > Paragraph > Borders > Bottom Border.

How do I remove the line?
Click in the header paragraph that has the border, open Home > Paragraph > Borders, and select No Border. If the line is a shape, select it while editing the header and press Delete. Make sure you have selected the line itself rather than deleting header text.

Should I use a border or a shape?
Choose a paragraph border for a reliable divider that follows the header paragraph and page margins. Choose a shape when the line needs a custom length, angle, or position. Shapes offer more freedom, but may need adjustment if the layout changes.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

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