Delete Header & Footer permanently

All documents in Word have Headers and Footers. By default, they are blank, but they are there.

Removing or deleting them deletes the content, not the document structure.

Here is a screen shot from a document after the Header has been removed using the Remove Header command. The Header structure is still part of the document.

You can change the space reserved for headers and footers and save that as default.

Layout > Page Layout > dialog launcher (little arrow in bottom right of group)

See Quick Reference Guide for Headers, Footers, and Page Numbers (pdf)
https://www.addbalance.com/word/download.htm#hfQuickReference

I do not recommend creating or saving a template to be your Normal.dotm template. Only Word can create a completely functioning Normal template; it does that whenever the template in the User templates folder is given a different name or deleted. https://www.addbalance.com/usersguide/templates.htm#Normal

Normally, the blank document template does not include header and footer content. You can open the template for editing and remove headers/footers.

Alternatively, you can exit Word and rename the Normal template which will revert to factory defaults; see "Option 5: Replace the Normal.dot or Normal.dotm global template file" (https://learn.microsoft.com/en-us/troubleshoot/microsoft-365-apps/word/issues-when-start-or-use-word#option5).

Word does not use headers and footers “by default” in new blank documents; they only appear if the template the document is based on already contains them. To stop them from appearing in new documents, remove them from the template being used (for example, Normal.dotm or any custom template).

On Windows, for a document that already has headers/footers:

1. Go to Insert > Header or Footer.
2. Select Remove Header or Remove Footer.
3. If the document has more than one section, repeat this for each section.
4. Save the file as a template (e.g., .dotx or .dotm) and base new documents on this template instead of the old one.

This way, new documents created from that template will have no headers or footers and nothing will need to be deleted manually.

References:

• Remove all headers and footers in Word
• Insert a header or footer