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FINOWL / PHONE VALIDATION

A phone number. Checked and formatted.

Validate a number in any common format and get it back in E.164, international and national formats, with its country, line type, original carrier and time zones. Parsed offline, with no call or text ever sent.

Start buildingTry the sandbox
Isometric phone number card connected to a phone block and number details.

HOW IT WORKS

One number in.
Clean details out.

A single request returns what your form, CRM or messaging workflow needs to decide what happens next.
STEP / 01

Send a number

Post a phone number in any common format, with an optional country hint for numbers without a + prefix.

STEP / 02

Parse it offline

Finowl checks the number against the numbering plan for its country, entirely on Finowl's own servers.

STEP / 03

Get number details

Receive a valid flag, standard formats, country, line type, original carrier, location and time zones.

SEE IT IN ACTION

From a number
to clean details.

POST/v1/phone/validate

RequestcURL
curl https://api.finowl.co/v1/phone/validate \  -H "Authorization: Bearer $FINOWL_API_KEY" \  -H "Content-Type: application/json" \  --data '{    "phone": "(415) 555-2671",    "country": "US"  }'
ResponseJSON200 OK
{  "phone": "(415) 555-2671",  "valid": true,  "possible": true,  "reason": null,  "country_code": "US",  "country": "United States",  "calling_code": 1,  "type": "fixed_line_or_mobile",  "e164": "+14155552671",  "international": "+1 415-555-2671",  "national": "(415) 555-2671",  "carrier": null,  "location": "San Francisco, CA",  "timezones": [    "America/Los_Angeles"  ]}

WHERE IT FITS

Better numbers,
from the first field.

Guide: sign-up fraud checks

  • Signup and checkout forms

    Catch numbers that are too short, too long or wrong for the country before the form is submitted.

  • CRM cleanup

    Store every number in E.164 format, so duplicates match and your calling and messaging tools agree.

  • Contact timing

    Use the line type and time zones to choose the right channel and call within sensible local hours.

A valid number matches the numbering plan for its country. It does not confirm that the number is in service or who answers it.

THE RESPONSE

Clear fields. Honest limits.

Every response tells you whether a number is valid, why not when it is not, and how to store and display it.

Carrier and location describe the number range, not the person, so keep them as context rather than facts.

Phone metadata from Google libphonenumber, licensed under Apache 2.0.

valid, possible, reason
Whether the number matches its country's numbering plan, whether its length is plausible, and why not, such as too_short or missing_country.
e164, international, national
The number in standard formats, such as +14155552671. Null when the number cannot be parsed.
country, country_code, calling_code
The country the number belongs to and its calling code.
type
mobile, fixed_line, fixed_line_or_mobile, toll_free, voip and other line types, or unknown.
carrier
The carrier the number range was originally allocated to. Ported numbers may now use another carrier.
location, timezones
A geographic description, such as San Francisco, CA, and the time zones the number can belong to.

A FEW GOOD QUESTIONS

Phone validation questions, answered.

Keep every number usable.

Validate and format phone numbers at signup or in your CRM, one request at a time.

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