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Phone Number Check
x402
Phone Number Check is a paid API for AI agents from api.facts402.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).
Validates and normalises any phone number worldwide, returning validity, E.164/national formats, country, type, carrier, location, and time zones — entirely offline and instant.
Price / call$0.01
Success—
StatusUnknown
How this service works
Use when an agent needs phone number validation for CRM, KYC or calling: valid/possible, E.164 and national formats, country, type (mobile, fixed line, toll-free, VoIP...), original carrier, location and time zones, for any number worldwide. Offline, instant. $0.01 USDC on Base; charged only on 2xx, never for invalid input.
Output
Returns whether the number is valid and/or possible, the canonical E.164 format, the national format, the ISO country code, the phone type (mobile, fixed line, toll-free, VoIP, etc.), the original carrier name, the geographic location, and one or more time zone identifiers. All results are computed offline with no external API call required.
Example use cases
CRM contact data cleanup
“I've got a phone number from a new lead — +1 (415) 555-0198 — can you validate it, confirm it's mobile and not VoIP, and give me the clean E.164 format to store in our CRM?”
KYC phone verification before onboarding
“As part of onboarding, I need to verify this user-supplied number: 07700900123, assuming they're in the UK. Is it a valid mobile number, and what carrier is it registered to?”
Outreach eligibility check for SMS campaign
“Before we send our SMS campaign, check if the number +33612345678 is a real, reachable mobile phone — not toll-free or VoIP — and tell me the country and time zone so we can schedule it appropriately.”
Technical details
Endpoint
POSThttps://api.facts402.com/phone?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need instant, offline phone number validation with rich metadata (type, carrier, time zone) rather than just format checking. It is ideal for CRM enrichment, KYC pipelines, outreach scheduling, and calling agents where you need to know whether a number is reachable and what type it is. It does not send an OTP or call the number — it does not verify the number is currently active, only that it is structurally valid and possibly reachable.
Side effects
- Number string fails pattern validation (not 3-40 chars of digits/symbols) — returns 400 validation error
- Ambiguous number with no +prefix and no default_region provided — may return invalid or misclassified result
- Unknown or fictional number — returns valid:false or possible:false with no carrier/location data
- Malformed input (wrong type, too short) — returns 422 or schema error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| number | string | Phone number, ideally in +E.164 form |
| default_region | — | ISO country used when the number has no +prefix |
Tags
x402
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