Data Source and Methodology

Phone number validation relies on globally recognized standards. The primary authoritative source for numbering plans is the ITU-T Recommendation E.164.

All calculations and format validations are based strictly on the formulas and structural rules provided by this standard. Carrier and line type information are simulated based on number patterns for illustrative purposes.

The Validation Process Explained

Validating a phone number is a multi-step algorithmic process, not a single equation. The logical flow can be represented as a series of conjunctive checks:

$$V = C_{format} \land C_{prefix} \land C_{length} \land C_{line}$$

Where each check must pass for the validation $V$ to be true:

  1. $C_{format}$: A Format Check, typically using a Regular Expression (Regex) to ensure the number adheres to the E.164 structure (e.g., ^\+[1-9]\d{1,14}$).
  2. $C_{prefix}$: A Prefix Check to identify a valid, known international country code.
  3. $C_{length}$: A Length Check to verify the number of digits is within the valid range for that specific country.
  4. $C_{line}$: A Line Type Check, which this tool simulates, to determine if the number is mobile, landline, VoIP, etc.

Glossary of Terms

Input

Phone Number
The full phone number you wish to validate. For global accuracy, it must be in the international E.164 format (e.g., +15551234567).

Outputs

Status
Indicates if the number is 'Valid' or 'Invalid' based on the combined validation checks.
International Format
The phone number, normalized to the E.164 standard (special characters removed).
Country
The country or territory associated with the number's prefix (e.g., +1 is 'United States / Canada').
Line Type (Simulated)
The simulated type of service for the number, such as 'Mobile', 'Landline', 'VoIP', or 'Toll-Free'.
Carrier (Simulated)
The simulated telecom provider associated with the number (e.g., 'AT&T (Simulated)').

How It Works: A Step-by-Step Example

Let's validate the input: +1 (555) 123-4567

  1. Normalization: The tool first strips spaces and special characters: (, ), , -. The resulting string is +15551234567.
  2. Format Check ($C_{format}$): The string +15551234567 is matched against the E.164 regex. It starts with + followed by digits. This check passes.
  3. Prefix Check ($C_{prefix}$): The tool extracts the prefix +1. This is identified as a valid prefix for 'United States / Canada'. This check passes.
  4. Length Check ($C_{length}$): The prefix (1 digit) and the number (10 digits) total 11 digits (excluding the '+'). This is a valid length for the +1 numbering plan. This check passes.
  5. Line Type Check ($C_{line}$): The tool simulates a carrier lookup for 5551234567. The 555 prefix is typically for fictional use, but our simulation might return 'VoIP' and 'Test Carrier (Simulated)'. This check passes.

Final Result: Since all checks passed, the tool displays a 'Valid' status with the corresponding country, line type, and carrier data.

Frequently Asked Questions

Is this phone validation tool free?

Yes, this tool is completely free to use. All validation and processing are performed locally in your browser for speed and privacy.

Do you store or sell my phone number?

Absolutely not. We respect your privacy. This tool operates entirely client-side. The phone number you enter never leaves your device and is not sent to our servers, stored, or logged.

What is E.164 format?

E.164 is the international standard for phone numbering plans. It ensures every number is globally unique. It consists of a plus sign (+), followed by a country code (1-3 digits), and the subscriber number (up to 12 digits).

Why is the carrier and line type 'Simulated'?

Determining the *actual* line type and current carrier requires a live, real-time database query (known as an HLR or LRN lookup). These services cost money and cannot be performed securely from a user's browser. Our tool *simulates* this data based on number patterns to provide a complete example of a validation result.

Can this tool detect spam or robocalls?

No. This is a number *validator*, not a *reputation* service. A number can be perfectly valid (correct format, active line) but still be used for spam. Reputation checks require complex, paid services that analyze call activity.

What does 'VoIP' mean?

VoIP stands for 'Voice over Internet Protocol'. It's a phone service that operates over the internet (e.g., Google Voice, Skype) rather than a traditional copper-wire landline or cellular network.

Why is the '+' country code required?

The + and country code are essential for universal validation. A number like (555) 123-4567 is ambiguous—it could be from the US, Canada, or several other territories that use 10-digit numbers. The +1 prefix makes it globally unique and verifiable.

Tool developed by Ugo Candido.
Content and methodology reviewed by the CalcDomain Editorial Board.
Last accuracy review: