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Phone Number Validator

Validate and format phone numbers according to the international E.164 standard for accuracy and consistency.

Phone Number Input

enter a phone number

Validation Result

Enter a phone number to see its validation result.

API Development

About Phone Validator

Parse and validate phone numbers against per-country numbering plans, normalising them to E.164 and reporting region, carrier hints, and likely line type. A number string alone is not parseable — 020 7946 0958 is a valid London landline and also a plausible fragment elsewhere, so parsing requires either a leading plus or an explicit default region.

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Frequently asked questions

What exactly is E.164 and why store numbers in it?
E.164 is the ITU format: a plus, a country calling code, then the national significant number, at most 15 digits total, with no spaces, hyphens, or brackets. It is globally unambiguous, which national formats are not — a bare 9876543210 could be Indian or American depending on context you may not have retained. Store E.164 and render the local format at display time. Storing the display format instead means every comparison, dedupe, and SMS send has to reparse with an assumed region.
Why does a number valid in one country fail in another?
Each country's numbering plan sets its own lengths, prefixes, and trunk conventions. India's mobile numbers are ten digits beginning 6 to 9; UK numbers vary from nine to ten digits after the 0 trunk prefix and split by area code; the NANP is a fixed ten digits where neither area code nor exchange may start with 0 or 1. A validator is really a table of these rules, and the rules change — new mobile prefixes and area codes are allocated regularly, so an old library rejects legitimately new numbers.
Why is mobile-versus-landline detection unreliable?
It works where the numbering plan reserves distinct ranges, as in India, the UK, and most of Europe. It does not work in the NANP, where mobile and fixed lines share area codes entirely and no prefix distinguishes them — the answer for a US number is genuinely unknown. Number portability erodes it further everywhere: a ported number keeps its original prefix while the service moves, so the range says where it was issued, not what it is now. Only an HLR lookup gives the current answer.
What is the trunk prefix and why does it break naive concatenation?
Many countries use a leading digit for domestic dialling that is dropped internationally — 0 in the UK and much of Europe, 1 in the NANP for long distance. Concatenating a country code onto a national number without stripping it produces +44 020 7946 0958, which is invalid. Italy is the notable exception: its leading 0 is part of the number and must be kept. This is why generic string manipulation fails and a library with per-country metadata is required.
Does validation mean the number is in service?
No. Validation confirms the number conforms to its country's plan and falls in an allocated range — nothing more. It cannot tell you whether the line is connected, whether it is a disconnected number recycled to someone else, or whether it belongs to the person entering it. Recycling is a real security concern for SMS-based recovery, since carriers reissue dormant numbers within months. Confirming reachability requires actually sending a message, or an HLR lookup against the network.