The field that will print a page number only on the last page is:
{IF { PAGE } = { NUMPAGES } "{ PAGE }" }


This will only work if page numbering has not been restarted.

If you are restarting page numbering at the beginning of a section, then try the { SECTIONPAGES } field instead of { NUMPAGES }.


To create this field, on the last page of your document, type the field without the field codes (or copy from below and paste):
IF PAGE < NUMPAGES "PAGE"
Then select each PAGE and Press Ctrl+F9, then F9 for each.


If you are on page 25 it should then look like this:


IF 25 = NUMPAGES "25"


Then do the same thing for NUMPAGES (or SECTIONPAGES). It should look like this:

IF 25 = 25 "25"


Then select the entire field (IF 25 = NUMPAGES "25") and Press Ctrl+F9, then F9


You should see 25.

If you copy and paste this field to any page other than the last page, nothing will show.

Copy the field.

Insert > Footer > Edit Footer.

Paste the field where you want it in the footer. If you have more than one footer, copy it to all of them. (Each section has three footers, even though you may not see them all.