Q: Duplicate leads keep getting rejected. How do I kill the duplicates at the source?

Q: Duplicate leads keep getting rejected. How do I kill the duplicates at the source?

A: Duplicates are a plumbing problem, so trace the pipe end to end:

— Check form double-fire: a button that submits twice on a slow connection creates instant dupes. Disable the button on click.
— Add client-side dedupe: hash the email on submit and block a second identical submit in the same session.
— Look at your pixel: a tracking pixel firing on page reload re-sends the lead. Fire once, on success only.
— Inspect sub-sources: a sub-source replaying yesterday's leads is fraud, not a glitch. Compare lead hashes across days.
— Set a server-side window: reject the same email/phone within, say, 24 hours at your endpoint, not just the network's.
— Measure again after each fix so you know which one mattered.

Short version: stop double-submits, fix the pixel, hash-dedupe server-side, audit sub-sources.

Still stuck? Drop your case in the comments.