Send Google Ads Lead Form Leads to LeadCentre

When someone submits your lead form, Google sends LeadCentre a JSON post. LeadCentre checks the key in the URL, applies your field matching and creates a lead, and the new lead alert goes out.

How the answers arrive

The answers sit in a list called user_column_data. Each entry has a column_id saying what it is, such as EMAIL, and a string_value holding the answer. LeadCentre flattens nested data into dotted names, so on the matching screen you see rows like these, with the latest value beside each:

user_column_data.0.column_id      FULL_NAME
user_column_data.0.string_value   Sam Lee
user_column_data.1.column_id      PHONE_NUMBER
user_column_data.1.string_value   +447700900123
user_column_data.2.column_id      EMAIL
user_column_data.2.string_value   [email protected]

What matching by position means

• Matching user_column_data.2.string_value to Email means "the third answer is the email". LeadCentre doesn't read column_id when it creates a lead.
• If a question is reordered or removed, answers land in the wrong fields. A phone number could sit in Email. There's no error, and the lead still arrives. Adding a question is only flagged if it creates a new position.
• Google's field reference doesn't promise an order for the list, so treat your first real lead as the check.
• Use one key per form, unless two forms ask the same questions in the same order. Google lets one URL serve many forms, but in LeadCentre the matching belongs to the key.
• After any form edit, look at the column_id rows on the matching screen and confirm each position still means what you matched it to.

If you change forms often or run many of them, route them through Zapier or Make instead. Zapier has a New Lead Form Entry trigger limited to one Zap per form, and you pick which answer goes under which name when you build the POST step. Check custom questions show up in its sample first. That adds another account and another paid step, so weigh it against how often your forms change.

Google's test data and LeadCentre's listening step

Google's Send test data button posts a fixed sample: a placeholder name, phone and email, marked is_test. It may not reflect your form's custom questions or real order. LeadCentre doesn't read is_test. What happens depends on the key:

• Listening on: it's recorded as Test data and never becomes a lead. Google gets its 200 and shows a green message. This is what you want.
• Listening off, nothing matched yet: it's held as Waiting for field matching, and becomes a placeholder lead when you save your matching.
• Listening off, already matched: it becomes a real lead immediately. The alert goes out, and an Instant Reply goes to the placeholder address if you've switched those on.

So press Listen for test data before every Google test, and Stop listening straight after. A real lead arriving while listening is on counts as test data too, and won't become a lead.

What Google expects back

Google wants an HTTP 200, which LeadCentre sends when a post is accepted. Google's guide says 5XX responses can be retried and 4XX responses aren't, so a lead sent to a replaced URL (a 401) won't be sent again. Those leads stay in Google Ads. Google says it stores leads for 60 days, with CSV downloads covering the last 30, so download them and call those people. LeadCentre has no CSV import.