I Want Footnotes to Break and Continue in Next Page
Why do my footnotes sometimes end up on a different page from their references in the text?
Or, I don't want my footnotes broken and continued on the next page; I want the whole footnote on the same page. How do I do that?
Keeping the start of a footnote on the same page as its reference
If you've ever tried to type (on a typewriter!) a page with footnotes, you know how hard it is to figure out how much space to leave for them. If you have a footnote reference in the very last line of a page, there will not be room for an extra footnote, and both reference and note will have to be carried to the next page. Or there may be room for the text reference and part of the note, but the remainder of the note will have to be continued on the next page. Sometimes it's hard to estimate how long the note will be, too. Word has to make all these same calculations. Admittedly it makes them a lot faster, but it's still a complex operation, and it's not surprising that sometimes it doesn't turn out quite right.
Some users have reported footnotes wandering uncontrollably. This was an admitted bug in Word 97 and earlier (and is most likely to be evident if you have "Keep lines together" switched on for your Footnote Text style, or if you have no Spacing Before or After in your Footnote Text style), and it results from the difficulty of calculating where page breaks will fall, especially in a document with complex formatting.
Most reliable fix (all versions of Word)
To keep a footnote on the same page as its reference, the only workaround that has been found to be always reliable (and this even includes Word 2000 and above) is to format the line spacing of the body text paragraphs (not the footnotes themselves) to an Exact amount (in the Paragraph dialog). As a reference point, Single line spacing is usually approximately 120% of the nominal point size for most fonts (12 pts for 10-point Times New Roman, for example), so Double would be 240%, and so on. The actual percentage varies widely between fonts (it can be less than 100% and as much as 130%), so some trial and error may be needed.
If you are using Multiple line spacing (double, triple, or some fraction), the extra space is added below the line. When you change to Exact line spacing the same amount of space will be added above the line. This extra space is not suppressed at the top of a page, so you may want to adjust your top margin accordingly.
Another thing that can help is to disable the option to "Use printer metrics to lay out document." In Word 2003 and earlier, this setting is found on the Compatibility tab of Tools | Options (Word | Preferences | Compatibility on the Mac). In Word 2007, use Office Button | Word Options | Advanced; scroll to the bottom and expand the "Layout Options" (click on the +). Note that Compatibility Options are per-document settings and will need to be changed for each document you want to fix, but you can change the settings for all new documents by clicking Default… in Word 2003 and earlier or selecting "All New Documents" for "Compatibility options for" in Word 2007.
Other fixes (Word 2000 and above)
First, the good news: The problem has been fixed for most (but not all) scenarios in Word 2000 and above and above, provided that you don't need your documents to be Word 97–compatible. If you still see the problem in a Word 2000 and above document, you can usually fix it by clearing the checkbox for "Lay out footnotes like Word 6.x/95/97" in the Compatibility Options.
In documents that were originally created in Word 2000 and above or above, this compatibility option is deselected by default; but it is selected by default when you open a document that was originally created in an older version of Word. It is also selected by default if you have checked "Disable features not supported by Word 97" under Tools | Options | Save (Word 2003 and earlier).
The bad news regarding this fix is that if you think you may ever need to send your Word 2000 and above document to someone using an older version, the bug will be evident when they open the document; so you will still need to use the Exact line spacing fix, or one of the fixes described below, if you need Word 97 compatibility.
Furthermore, there are actually some scenarios in which footnotes wander in Word 2000 and above (with the Word 2000 and above compatibility options set), but don't wander in Word 97 (or in Word 2000 and above with the Word 97 compatibility options set)! This happens when the final line on a page contains a footnote reference, and the paragraph has the "Widow/Orphan control" setting switched on, and where having the footnote on the same page as its reference would force that line onto the next page, breaking the "Widow/Orphan control" rule. (Note that "Widow/Orphan control" is switched on by default for both the Normal and Body Text styles—and for very good reasons).
Rather than override the Widow/Orphan control setting and force the bottom line onto the next page, (or perhaps better still, force the entire paragraph onto the following page), Word gives you wandering footnotes in this scenario. The only reliable fix is to define the style you use for your body text to have Exact line spacing, as described above. It usually does less damage to define the style to instead have Widow/Orphan switched OFF and "Keep lines together" switched ON. This leads to more modern layout. Documents these days tend to have shorter paragraphs, and modern readers are more impatient with having to chase the rest of the paragraph to the next page—it disturbs their concentration.
For an example which illustrates this problem, download the attached file Fnote.zip, which extracts to Fnote.doc, and open that in Word 2000 and above or above. You will find that footnote 5 is on a different page from its reference. If you set the compatibility options to Word 97, you will find that the footnotes are on the same page as their references. Alternatively (and a more reliable fix), if you redefine the Body Text style to have Exact line spacing of 14.4 points, the footnotes will be on the same page as their references.
Other fixes (Word 97 and below)
As already discussed, using Exact line spacing for body text is the most reliable fix; but as an alternative, you can reduce the chances of encountering the problem by making sure your Footnote Text style has the "Keep lines together" property switched off.
You can also reduce the risk of encountering the bug by defining your Footnote Text style to have Spacing Before or After. If you want any spacing between paragraphs, it should be so defined in any case (as opposed to the alternative of inserting empty paragraphs).
Some other workarounds are also covered in the Microsoft Knowledge Base articles "WD97: Footnote Moved to Next Page" and "WD2000: Footnote Moved to Next Page"; but with them (as they say), YMMV.
Keeping an entire footnote on the same page
Keeping an entire footnote on the same page is somewhat easier but involves aesthetic considerations. You can set the "Keep lines together" property for a given footnote paragraph or for the Footnote Text style, and this will ensure that footnotes are not broken because the text reference and the entire note will be carried to the next page. But the previous page will end short (very short if the footnote is very long), which may be even less desirable than breaking the footnote. It's up to you to decide. For more on this, see "Improving the bottom line: toward a more uniform bottom margin."
Special case: footnotes in tables
Footnotes in tables can generate additional problems. By convention, footnotes to tables should appear at the foot of the table rather than at the foot of the page, [1] so one way to avoid problems is to insert them manually, using superscripted letters or other symbols in the table text and collecting the footnotes in a single bottom row (with merged cells).
If you choose to use automatic footnotes, however, be aware that Word will place a footnote on the page where the cell in which the reference occurs ends . This means that, if the cell extends across a page break, the reference may be on one page and the footnote on the next. This in itself is a problem, but where it becomes extremely bizarre is a situation where a single row is allowed to go on for several pages and contains multiple footnote references. The page where the row ends may not have enough space for all the footnotes. Instead of carrying the excess over to the next page, Word just dumps them. That's right: they simply disappear (they can be seen in the footnote pane but not in Print Layout view, and they do not print).
What this means in a practical sense, then, is this: If you choose to use automatic footnotes in a table, make sure that your rows are not too deep. It's best to start a new row at least once a page (Word has problems with very long rows even without footnotes), and a new row for each paragraph would be the ideal.
See also:
"I want the numbers in my footnotes not to be superscripted, and I want the numbers to be followed by a dot and a tab"
"I have a footnote reference in a column, and I want the footnote to span both columns. Is this possible?"
[1] Chicago Manual of Style, 15th ed. (Chicago: University of Chicago Press, 2003), 13:43: "Table footnotes always appear immediately below the table they belong to and must be numbered separately from the text notes."
Source: https://wordmvp.com/FAQs/Formatting/FootnoteOnDiffPage.htm