A form and a CRM card are one request in two places until they share an id. Without that, someone retypes the fields, and the client cannot see what happened to the request.
What to send
Not every input on the form. Send what the team works from: contact, product or service, comment, source, page, consent. Campaign fields belong in their own columns, not in the comment.
The link can run back as well: a deal status updates the client’s account. That needs the same id on both sides.
How a lead gets lost
The CRM will be down sometimes. The form should still save on your side, and delivery should retry. A webhook with no queue drops the evening’s leads the moment the API returns an error.
Duplicates need a rule — phone or email plus a time window — or one click creates three deals.
Example
A calculator sends the configuration, the total, and the contact. The CRM opens a deal with line items, not the sentence “customer wants a kitchen”. The manager edits the discount there. The email the client receives matches the deal.
The integration is done when you can point at a request on the site and open the same card in the CRM.