New: check signups in Auth0 before the account is created

Catch bad signups and bad leads before they cost you.

Check emails, phone numbers and IPs by API or CSV upload. Every record comes back as allow, review or block, with the reasons.

Start 7-day trial See the API

500 checks free for 7 days · Card required · Then $99/month for 20,000 checks · Cancel anytime.

Protect your signups

Block throwaway inboxes and flag data-center and Tor traffic before you hand out trial credits. Works with your API, Auth0 or AI agents (MCP).

Clean your lead lists

Upload a CSV of leads and get every row back flagged: dead domain, throwaway inbox, role address or invalid number. Find the contacts you can't reach before you pay to email or call them.

app.lookupdock.com / checks

Signup and lead-list checksExample data

Signup check

[email protected] · 203.0.113.42 · +44 20 7946 0123

Allow

Domain receives mail; no hosting-network match or Tor exit; valid UK fixed-line number.

email.mx_found: true
email.disposable: false
email.role: false
email.catch_all: null
ip.hosting: false
ip.tor: false
ip.vpn: null
ip.asn: 64512
phone.valid: true
phone.line_type: fixed line
phone.carrier: null
phone.active: null

Illustrative data. You choose what allow, review and block do.

One call. One decision.

Send email, phone and IP together. Get allow, review or block, plus every signal behind it.

You decide the policy: ask for extra verification, hold the trial credits, or block outright.

Unknown stays unknown. We never guess a field, and you're never charged when we fail.

Where fake signups come from

Throwaway inboxes.

About 10,000 known disposable domains, refreshed weekly, plus a live check that the domain can actually receive mail.

Live: domain, disposable, role and free-provider checks

Server and anonymised traffic.

Signups from 13 major cloud and hosting networks and from Tor exits, refreshed daily, are flagged for review.

Live: location, network, hosting and Tor

Fake numbers.

Malformed and impossible phone numbers are rejected for every country. Outside the US and Canada you also see whether it's mobile, landline or VoIP.

Live: validity, format, country and number type

$99/month for 20,000 checks.

About $0.005 a check, with no overage charges. 7-day trial with 500 checks.

See the plan and trial details

What it checks, and what it doesn't

Checks today

Email syntax, mail-domain DNS, disposable, role and free-provider flags.
IP location, network owner, 13 major cloud and hosting networks, and Tor exits.
Phone validity, format, country, and number type outside the US and Canada.

Coming soon

Mailbox verification
Live carrier and US/Canada line type

Not offered: VPN detection.

Signals help you decide; they don't prove fraud or identity.

Three endpoints. One response shape.

Idempotency keys. Retry safely; a repeat never runs or charges twice.
null means unknown. A missing field is never filled with a guess.
Free when we fail. Supplier errors and timeouts cost 0 credits.
OpenAPI 3.1. Generate a client in any language. Read the reference

curl -X POST https://lookupdock.com/api/v1/phone \
  -H "Authorization: Bearer $LOOKUPDOCK_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"value": "+442079460123"}'

{
  "request_id": "req_sample_phone",
  "mode": "demo",
  "status": "completed",
  "service": "phone",
  "credits_consumed": 0,
  "data": {
    "valid": true,
    "possible": true,
    "formatted": "+442079460123",
    "country": "GB",
    "country_calling_code": "44",
    "region": "London",
    "line_type": "fixed line",
    "carrier": null,
    "ported": null,
    "active": null,
    "uncertain": true,
    "check_level": "basic",
    "source": "numbering_plan",
    "metadata_version": "phonelib-0.10.28",
    "sample": true
  },
  "error": null
}

curl -X POST https://lookupdock.com/api/v1/email \
  -H "Authorization: Bearer $LOOKUPDOCK_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"value": "[email protected]"}'

{
  "request_id": "req_sample_email",
  "mode": "demo",
  "status": "completed",
  "service": "email",
  "credits_consumed": 0,
  "data": {
    "valid": null,
    "deliverability": "risky",
    "disposable": true,
    "role": false,
    "free": false,
    "mx_found": null,
    "catch_all": null,
    "reason": "disposable_domain",
    "uncertain": true,
    "sample": true
  },
  "error": null
}

curl -X POST https://lookupdock.com/api/v1/ip \
  -H "Authorization: Bearer $LOOKUPDOCK_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"value": "203.0.113.42"}'

{
  "request_id": "req_sample_ip",
  "mode": "demo",
  "status": "completed",
  "service": "ip",
  "credits_consumed": 0,
  "data": {
    "country": "US",
    "city": "Sample city",
    "asn": 64512,
    "network": "Documentation network",
    "hosting": false,
    "tor": false,
    "vpn": null,
    "proxy": false,
    "uncertain": true,
    "attribution": "IP geolocation by DB-IP (https://db-ip.com); CC BY 4.0",
    "sample": true
  },
  "error": null
}

Check your next signup.

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