Word: Outline numbered headings start at a number other than 1

A client has a 300+ page document that goes back to their client, and then into that client’s SharePoint system where many authors work on it. Occasionally the outline numbering goes awry. Instead of Heading 1s (H1) starting from 1, they might start from 15, so the first section heading is 15 instead of 1 and the second is 16 instead of 2 etc. Added to this, the Heading 2 (H2) and Heading 3 (H3) numbers have also started from another number (e.g. H2 might start at 4, so you get section 1.4 as the first H2 in section 1, with 1.5 as the next; H3s might start from 8, so instead of 1.1.1, you might get 1.1.8 followed by 1.1.9).

I haven’t figured out what causes this behaviour (both my client and I suspect SharePoint!), but after the first time I got it on their document, I tried all sorts of things before finding a way to fix it.

First I tried right-clicking on the headings and selecting Restart at 1. That didn’t work. Then I tried setting the numbering via the styles. That didn’t work either. What did work was resetting the start number under the Multilevel List numbering settings. Here’s how:

1. Put your cursor at the first letter after the heading number.
2. Go to Home > Paragraph and click the drop-down arrow next to the Multilevel list numbering icon.
   
3. Click Define New Multilevel List.
   
4. On the Define New Multilevel List window, click More.
   
5. On the right of the window, find the Start At value and change it to 1. DO NOT change anything else on this screen – there lie dragons!!!
   
6. Click OK.
7. If the erroneous numbering was for Heading 1, then you don’t need to do anything more. But if it’s for Heading 2 (if H1 is wrong, H2 and possibly H3 likely will be too), then you’ll need to repeat these steps for the FIRST H2 in EACH new H1 section—getting it right for the first one will auto flow through to the other H2s in that section. Same if H3 is wrong—go to the first H3 in EACH H2 section and repeat the steps.