← Form tracking demos Click ID arrives

2 · Hidden field

The form ships with a hidden input whose default value is the placeholder. When the Tracking Tag runs it replaces that text with the real Click ID, so the value travels with the lead into the CRM.

What to look for. The inspector shows the live value of name="click_id". With the Tag running it reads as a long random string; with the Tag absent or blocked it still reads --CLICK-ID--. Submit either way and the thank-you page prints exactly what was sent.

The catch. Substitution happens once, when the page loads, and only in forms the Tag can reach. Everything on this page is plain HTML present at load, which is why it works. Scenarios 5 to 8 break each of those conditions in turn.

The markup

<form action="/thank-you.html" method="get" name="optin">
  <input type="hidden" name="click_id" value="--CLICK-ID--">
  <input type="text"   name="fname">
  <input type="email"  name="email">
  <input type="submit" value="Submit">
</form>

CRM side. The receiving system needs a custom field to hold this value — create it before wiring the form up, otherwise the Click ID is dropped on arrival.