When you update a TOC, you will be asked to choose whether to update the whole thing or just page numbers.
Once you've built your TOC, you'll probably have to maintain it. If you include more headings in your document, or simply add more content, you'll want the TOC to include the new headings and show the right page numbers.
You update the TOC by selecting the TOC, and then pressing F9 or clicking the Update TOC button on the Outlining toolbar.
Tip To open the Outlining toolbar, click the Show Outlining Toolbar button in the Index and Tables dialog box, or on the View menu, point to Toolbars and then click Outlining.
When you update the TOC you will be asked if you want to update the entire TOC, including all the text entries, or just the page numbers. Choose the page numbers option only if you've been adding body text but no new headings — it's faster and will save you time in a long document. But if you've added a new heading or changed any text included in the TOC, choose the Update entire table option.
Avoid editing entries in the TOC itself — if you ever update the TOC you'll lose those changes. To change text that appears in the TOC, be sure to edit this text in the body of the document — not in the TOC, and then press F9 to compile the changes.
Tip Always update a TOC as the last thing you do to a document before printing or sending it out; that way you'll always include any last minute changes.