Nothing humbles a paid-acquisition report like pulling a sample of leads and calling them yourself. Half the time the number rings to a fax line, a disconnected recording, or “the person you are trying to reach.” You paid for those. Whether the spend runs through Google Ads, Facebook Lead Ads, or an affiliate network, fake form submissions drain budget, pollute your CRM, and waste the one resource your sales team cannot get back: time on the phone. Industry reports put 10 to 25 percent of paid-channel leads in the invalid-or-fabricated bucket, and the phone number is usually the field that gives them away.
Validating that number at the form, in real time, catches the junk before it enters your funnel. Your spend goes further and your reps only dial contacts worth dialing.
Where fake leads come from
Bot traffic
Automated bots fill forms at scale. Some hit competitors’ ads to burn their budget. Others harvest confirmation pages to feed phishing and spam lists.
Incentivized submissions
Contests, giveaways, and gated downloads pull in low-intent entries. People drop in a throwaway number to grab the content with no intention of ever picking up.
Affiliate fraud
Pay-per-lead deals reward volume over quality, and that incentive is exactly as corrosive as it sounds. The dishonest publishers manufacture leads with VoIP numbers, recycled contacts, and automated form fillers.
Manual junk
Real humans typing fake numbers to dodge a sales call is more common than people admit. “555-555-5555” and its cousins show up in every lead database I have ever audited.
What validation actually catches
Validate the number on submit and you can detect:
- Invalid numbers that do not exist or fail format checks
- Disconnected lines that were once real but are now suspended or deactivated
- VoIP and disposable numbers bought in bulk from the services fraud rings favor
- Landlines, which are dead weight if your follow-up runs over SMS
- Geographic mismatches, where the number’s region and the user’s IP disagree
CheckThatPhone returns all of these signals in one API call that finishes in milliseconds, fast enough to run before the form submission completes.
How to put it to work
1. Validate on form submit
Add the API call to your lead-form handler. Before the lead hits your CRM or kicks off a nurture sequence, validate the number and reject or flag anything that fails. Flag rather than hard-reject when you are not sure; you can always downgrade priority instead of throwing a real lead away.
2. Set rules per campaign
Different campaigns deserve different thresholds. For high-value B2B, block VoIP outright and require mobile. For broad consumer lead gen, allow VoIP from established carriers but block the disposable services. For contest entries, accept any valid number but flag VoIP for lower-priority follow-up.
3. Track quality by source
Log validation results next to your attribution data. Give it a few weeks and the pattern is obvious: certain channels, publishers, and campaigns produce far more invalid numbers than others. That is your signal to move budget away from them.
The economics
The math is what makes this an easy call. Say you generate 5,000 leads a month at $20 CPL and 15 percent are fake. That is $15,000 a month in spend buying nothing. Validating every lead at $0.001 per lookup runs you $5. You do not need a spreadsheet to see which side wins.
Getting started
Fake leads rot your marketing ROI from the inside, quietly, until you go looking. Put validation on your capture forms and you catch the bad submissions in real time so your team only works contacts that are real and reachable. Read the API documentation to wire it into your forms, or explore pricing plans to pick a tier. Start by logging validation results on your highest-spend campaign, find the worst source, and cut it.