Phone number formatter (E.164)
Short answer: Converting a phone number to E.164 means stripping out spaces, dashes and brackets, dropping the national trunk prefix (typically a leading 0), then prepending + and the country code. The UK number 07700 900123, for instance, becomes +447700900123. The formatter below handles this across 181 countries.
Type a number in however you'd normally write it locally, pick the country, and the tool hands back the international E.164 version while checking that the digit count is right.
How to format a number by hand
- Strip out anything that isn't a digit — spaces, dashes, dots, brackets.
- If the number leads with the country's trunk prefix (0 across most of Europe, Asia and Africa), drop it.
- If it already starts with an international access code (00 or 011), take that out as well.
- Add + followed by the country calling code at the front.
- Verify the length — no more than 15 digits after the +.
Examples
| Written locally | Country | E.164 |
|---|---|---|
| 07700 900123 | United Kingdom (+44) | +447700900123 |
| (212) 555-0142 | United States (+1) | +12125550142 |
| 030 12345678 | Germany (+49) | +493012345678 |
| 98765 43210 | India (+91) | +919876543210 |
Why E.164 matters
WhatsApp, Telegram, SIP systems and SMS gateways all store numbers in E.164. Keep a number in its local format instead, and it can miss verification codes entirely, or stop matching your contact list once you've crossed a border.
Frequently asked questions
What does the formatter check?
It strips out formatting characters and the trunk prefix, prepends the country code, and compares the resulting digit count against the usual national number length for that country.
Does it tell me if a number is active?
No — it's a format check only, with no lookup against any network.
Is my number sent anywhere?
No. All formatting happens locally in your browser.
Where do I find a country's code?
Check the complete list of 181 countries on the country calling codes page.
Related pages
- Country calling codes (181 countries)
- What is E.164?
- Phone numbers by country
- SIP dialer setup
- Pricing
- Verification code not received?
Sources
- ITU-T Recommendation E.164 (as of September 2026)