Phone format validation API

Check phone number structure and return consistent formats.

Use E.164, international or national output before saving the number or running further checks.

Part of: Form verification Data cleansing Source audit

What it checks

Phone format validation checks a submitted number against numbering-plan data for its country.

It tells you whether the number has a valid structure and sits in a valid number range, and returns the same number in standard formats. No network is contacted, so the result describes the number's format and range, not whether the line is active, who holds it or whether it is safe to contact.

Use it to catch typing errors at the point of entry, store numbers in one consistent format and decide which numbers are worth sending on to further checks.

What it returns

Field	What you get
valid	Whether the number is valid for its country's numbering plan.
country	ISO country code, country name and international calling code.
format	The number in E.164, international, national and RFC 3966 (tel:) formats.
assignedNetwork	The network the number range is assigned to, where range data includes it.
input	The number exactly as you submitted it.

assignedNetwork comes from number range data. A number can be ported to another network after it is assigned, so the network serving it today can be different. HLR phone verification returns the current serving network where available.

When to use it

On a form, to catch mistyped or incomplete numbers while the customer is still there to correct them.
Before saving a number, to store it in E.164 so records from different sources match.
When cleaning an existing list, to separate numbers that need correcting from numbers ready for further checks.
As a first step before HLR phone verification or TPS/CTPS screening.

What it does not confirm

A valid result means the number is correctly structured for its range. It does not show that the line is active or that the person can be reached. Use HLR phone verification for network status.
It does not show who holds the number.
It does not show whether you may call the number for marketing. Use TPS/CTPS screening for UK numbers.

How to read the result

Result	Meaning	What to do
valid: true	Meaning: The number is correctly structured for its country.	What to do: Store the E.164 format. Send it on to HLR phone verification if you need to know whether the line is active.
valid: false or a validation error	Meaning: The number is not valid for its range, or could not be read as a phone number.	What to do: Ask for the number again at the point of entry, or set the record aside for correction.
Unexpected country	Meaning: The number belongs to a country you did not expect.	What to do: Check whether the country code was entered correctly before relying on the number.

API & bulk usage

Send a single number to POST /api/validate/phone-basic for a real-time format check. International format with a country code gives the most reliable result. For files, the bulk uploader runs format validation as part of Phone validation, where HLR is an optional extra you can turn on for the same file.

Example from the API documentation

POST https://api.provero.io/api/validate/phone-basic

Request

{
  "phone": "+447700900123"
}

Response

{
  "input": "+447700900123",
  "valid": true,
  "country": {
    "code": "GB",
    "name": "United Kingdom of Great Britain and Northern Ireland",
    "callingCode": "44"
  },
  "format": {
    "e164": "+447700900123",
    "international": "+44 7700 900123",
    "national": "07700 900123",
    "rfc3966": "tel:+44-7700-900123"
  },
  "assignedNetwork": "Example Mobile Network"
}

Illustrative example. +447700900123 is from a range reserved for drama and documentation, and the network name is a placeholder. assignedNetwork is returned only when range data includes it.

Read the Phone format API documentation →

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Related checks

No single check settles whether a record can be trusted. These are the ones people usually run alongside Phone format validation, each answering a different question about the same record.

See every Provero check →

Phone format validation FAQ

Which formats does it return?

E.164 (for example +447700900123), international (+44 7700 900123), national (07700 900123) and an RFC 3966 tel: URI. E.164 is the usual choice for storing numbers and passing them to other services.

Does a valid result mean the number can be reached?

No. It means the number is correctly structured for a valid range. A valid number can still be disconnected, switched off or unused. HLR phone verification checks the number's status with the mobile network.

Will it tell me the current network for a ported number?

No. assignedNetwork is the network the number range was assigned to. If the number has been ported, the network serving it now can be different. HLR phone verification returns the current network where available.

Is phone format validation free?

Yes, it's free to start, so you can validate and normalise numbers from your first request, with no card required.

Start with this check

Create a free account, claim your credits and run Phone format validation through the API or bulk upload. No card required.