Phone number validation is the process of checking the validity of phone numbers. A phone number validation tool takes a number as input, performs a number check against national numbering plans, and returns data points like country, carrier and line type.
This guide covers three types of validation. Each type provides a different level of phone number check with different data points.
TL;DR
1. Number validation is fast, comprehensive, costs less, but returns fewer data points.
2. Network validation is slower, costs more, has less coverage but provides more data.
3. User validation provides the explicit consent of a user to be reached on a particular phone number. It costs even more and provides no extra data points.
1. Number Validation
This is the most comprehensive and fastest level of validation, where the goal is to check phone number eligibility against a country's telecom authority records. A phone number validator confirms that a number is approved and assigned to a carrier and line type.
A valid phone number is one that is approved by telecom authorities and assigned to a carrier and line-type, but not necessarily currently active. Number validation is the foundation of any phone number lookup or carrier lookup workflow.
Pros
Covers 100% of all numbers used worldwide
Very fast, typically on the order of milliseconds
Costs as low as $0.1 per 1,000 validations
Reveals the original carrier and line-type
Cons
No guarantee that the number is currently active
Ported and roaming carriers are not detected
2. Network Validation (Mobile Number Verification)
Network validation involves contacting the carrier to inquire about the current state of the phone number without contacting the number itself. This form of mobile number verification connects directly to the telephone network to reveal if the number is active, the name of the current carrier and the roaming status.
Pros
Reveals if the number is assigned and active
Reliable source of carrier identity for mobile numbers
Cons
Limited coverage: mobile numbers only, covering fewer than 85% of carriers
Slow: can take several seconds per validation
Higher cost: carriers charge per query
3. User Validation (Phone Verification)
The next level of phone verification is to check that the phone is ready to receive text or voice communication and that the user who provided a number can actually be reached on that number. This approach sends a numeric code by voice or text message to the phone number and requests the owner to return the code via the web or a mobile app.
Pros
Validates that the phone number is active and online
Validates that a user can be reached on the number
Validates user consent
Cons
Higher cost: message cost plus provider markup
Slow: requires user interaction, can be a deterrent
Conclusion
No validation method is perfect on its own. Depending on the use case, one, two, or all three methods must be combined to achieve the desired outcome.
Number validation is a no-brainer. Any workflow can benefit from this step to exclude invalid numbers before pursuing deeper checks at the next two levels. Whether you need to check phone number formatting, perform a free carrier lookup, or run a US phone number lookup, start with number validation as the baseline.
Frequently Asked Questions
Use a phone number validation tool like Veriphone. Enter the number or call the API to check phone number validity against the country's numbering plan. The tool returns whether the number is valid, plus carrier and line type data.
A phone number checker is a number validator that determines whether a given number conforms to the numbering rules of its country. It is distinct from phone verification, which confirms that a number is active or reachable.
A carrier lookup queries the numbering plan database to find the service provider for a phone number. The lookup returns the original carrier assigned to the number block. For ported numbers, network validation is required to identify the current carrier.
Veriphone offers 1,000 free credits on signup. Each credit performs one phone number lookup, including validation, formatting, and carrier detection. Free carrier lookup covers all 249 countries and territories.
Yes. Veriphone supports phone number check for 249 countries and territories including US and Canadian phone number lookup, with full carrier and line-type data for all regions.