How do I convert phone numbers to E.164 format?

Paste them into the formatter above, one per line or as a CSV, choose the country for numbers without a + code, and press Format numbers. Each valid number comes out as a + followed by the country code and the national number with no spaces, for example +14155552671. Download the result as CSV.

What is the correct format for a phone number?

Store it in E.164: a +, the country code and the national number with no spaces, such as +442079460958. Show it to people in international format, +44 20 7946 0958, or in national format, 020 7946 0958, when every reader is in that country.

What is the US phone number format?

Nationally it is written (415) 555-2671: a three-digit area code, a three-digit exchange and four digits. In E.164 the same number is +14155552671, with the country code 1 in front and no punctuation.

What is the UK phone number format?

Inside the UK, numbers start with a 0, such as 020 7946 0958 or 07911 123456. Internationally the 0 is dropped and +44 is added: +44 20 7946 0958, or +442079460958 in E.164.

Can I format phone numbers in a CSV without losing other columns?

Yes. Upload the CSV and the tool finds the phone column, formats it, and adds the formatted number, E.164, country, extension and status as new columns. Every original column stays in the download in its original order.

Does a valid format mean the phone number works?

No. It means the number fits an allocated range in its country's numbering plan. Whether the line is in service, who the carrier is and whether it is mobile or landline can only come from a live carrier lookup, which this free tool does not do.

Why did some numbers fail to format?

Usually one of three things: a digit is missing or extra, the default country is wrong for a number written without a + code, or the prefix isn't allocated, which is common with test and made-up numbers. Those rows are kept and labelled so you can fix them.

Is my list sent to a server?

No. Formatting runs in your browser with Google's open-source libphonenumber data, the same data Android uses. Nothing you paste or upload leaves your device.

Phone number formatter: convert a list to E.164

A phone number formatter turns numbers written any way into one consistent format. This one converts a list or CSV to E.164 (+14155552671), international, national or a tel: link. Pick a default country for numbers written without a + code, paste or upload, and download the result. It runs in your browser on Google's open-source libphonenumber data.

Phone numbers, one per line, or a CSV with a phone column

Upload a CSV or TXT fileRuns in your browser. Nothing is uploaded.

Default country

Used for numbers written without a + country code.

Output format

E.164 is what CRMs, dialers and SMS tools expect.

SimpleAPI

Sample result

(415) 555-0132 becomes +14155550132, its E.164 format, and the US format checks out.

Formatted: +14155550132
Input: (415) 555-0132
Country: US

What this means for you

One consistent format lets your CRM, dialer or SMS tool import the list without errors.

Next step:Remove duplicate numbers

E.164, international, national or tel: output
Extensions kept in their own column
Flags wrong lengths and unallocated prefixes
Download all rows or only the valid ones

E.164
Bulk
CSV

By SimpleVerifier Team · Last updated October 17, 2026 · Runs in your browser; nothing you paste is sent to us

How do I format a list of phone numbers to E.164?

Pick the default country. Numbers written with a + code ignore it; local numbers like (415) 555-2671 or 020 7946 0958 use it.
Choose the output format. E.164 is the safe choice for CRMs, dialers and SMS platforms.
Paste one number per line, or upload a CSV. In a CSV the phone column is found automatically and your other columns are kept.
Press Format numbers, check the rows marked as problems, then download all rows or only the valid ones.

Example

You enter: Three numbers, (415) 555-0132, +1 (212) 555-0100 ext. 42 and 555-1234, with United States and E.164 chosen.
You get: +14155550132, and +12125550100 with extension 42 kept in its own column; 555-1234 is marked as a problem because its length is wrong for a US number.
Limits: Uploaded files can be up to 25 MB; there is no cap on the number of rows, and it all runs in your browser.

What is E.164 phone number format?

E.164 is the ITU's international numbering standard: a +, the country calling code, then the national number with no spaces, brackets or trunk prefix, at most 15 digits in total (ITU-T E.164). (415) 555-2671 in the US becomes +14155552671; 020 7946 0958 in the UK becomes +442079460958, dropping the leading 0.

SMS platforms, dialers and most CRM integrations expect this form because it is unambiguous. A number stored as 07946 095800 means nothing without knowing the country, and two copies of the same contact written differently will not match as duplicates. Our guide to the E.164 format covers the edge cases.

What is the correct international phone number format?

For storing and sending, the correct format is E.164; for showing a number to people, use the international format, which is the same digits grouped with spaces: +1 415 555 2671 or +44 20 7946 0958. The grouping follows each country's own convention from libphonenumber, so you don't have to know where the spaces go in Japan or Brazil.

The national format is how the number is written inside its own country, with the trunk prefix: (415) 555-2671 in the US, 020 7946 0958 in the UK. Use it only when every reader is in that country. The tel: option produces an RFC 3966 link such as tel:+14155552671 for click-to-call buttons on a web page. Country-by-country rules are on US phone number format, UK phone number format and the other phone formats by country.

How do I format phone numbers without a country code?

Pick the default country: every number without a + code is read as a local number in that country. A number written with a + code carries its own country, and the default is ignored. So does one written with the default country's own international dialling prefix, such as 00 from the UK or 011 from the US; a 00 prefix with a US default is read as part of a US number and fails. Pick the country most of your list is from and fix the exceptions by hand.

If your list mixes countries without codes, there is no reliable way to tell a UK mobile from an Australian one by the digits alone. The safe approach is to split the list by the country column in your CRM and format each part with its own default. To add or strip the + code on a list that is already clean, use add or remove country code.

What is a valid phone number format?

A valid phone number format is one with the right length for its country and a prefix in an allocated range of that country's numbering plan; that is what "Valid format" means in the status column. It does not mean the line is connected or in service: disconnected numbers stay in valid ranges, and ported numbers keep their digits.

"Right length, unallocated prefix" is usually a typo in the area code, or a made-up number. "Wrong length" is usually a missing or extra digit, or the wrong default country. Those rows still come out in the download with an empty formatted column, so you can fix them rather than lose them.

Extensions such as ext. 42 are kept in their own column, because E.164 has no place for them. If you need the line type (mobile, landline or VoIP) for compliance or SMS, the digits are not enough in countries like the US where both share area codes; that takes a carrier lookup.

How do I change phone number format in Excel or Google Sheets?

Excel's Format Cells > Special > Phone Number changes how a 10-digit US number is displayed, not what is stored, and formulas handle one country's pattern at a time. For a mixed export, the differences add up:

	This tool	Excel or Sheets
Countries	Every country in libphonenumber's data	One formula per country pattern
Output	E.164, international, national or `tel:`	Special format is display only; the cell keeps the raw number
Leading `0` or `+`	Read correctly	Dropped when the cell is stored as a number
Wrong length or bad prefix	Flagged with a reason	Formatted anyway
Extensions	Moved to their own column	Mixed into the digits

A Google Sheets formula for US numbers only, with no validation: ="+1"&RIGHT(REGEXREPLACE(TO_TEXT(A2),"\D",""),10).

Who uses this tool, and for what?

SMS teams: SMS platforms expect E.164 on every recipient. Format the list here first, so numbers missing a country code or a digit are caught before they become failed sends, then check the message length with the SMS character counter.
Sales ops: CRM imports from reps, events and enrichment vendors arrive as (415) 555-2671, 415.555.2671 and +1 415 555 2671. One E.164 column makes them match, so you can remove duplicate phone numbers and route by country.
Marketers: Sign-up forms collect numbers typed every possible way. Format the export with the form's main country as the default, download the valid rows, and send the problem rows back for review instead of importing them.
Agencies: Client lists come from many countries and tools. Split them by country, format each part with its own default, and hand back one CSV with the original columns plus E.164, country and status.

What can’t this tool tell you?

"Valid format" means the number fits its country's numbering plan. It cannot tell you the line is in service, who holds it, or that it can receive a text.
One default country per run. Local numbers from other countries in the same list are misread or fail, so split mixed lists first.
A typo that lands in another allocated range formats cleanly and stays wrong. Only the person or a carrier lookup can catch that.
Numbering plans change. Ranges opened after the bundled libphonenumber data was released can show as unallocated until it is updated.
E.164 has no field for extensions, so they go in their own column and are left out of the E.164 value.

Common questions

How do I convert phone numbers to E.164 format?: Paste them into the formatter above, one per line or as a CSV, choose the country for numbers without a + code, and press Format numbers. Each valid number comes out as a + followed by the country code and the national number with no spaces, for example +14155552671. Download the result as CSV.
What is the correct format for a phone number?: Store it in E.164: a +, the country code and the national number with no spaces, such as +442079460958. Show it to people in international format, +44 20 7946 0958, or in national format, 020 7946 0958, when every reader is in that country.
What is the US phone number format?: Nationally it is written (415) 555-2671: a three-digit area code, a three-digit exchange and four digits. In E.164 the same number is +14155552671, with the country code 1 in front and no punctuation.
What is the UK phone number format?: Inside the UK, numbers start with a 0, such as 020 7946 0958 or 07911 123456. Internationally the 0 is dropped and +44 is added: +44 20 7946 0958, or +442079460958 in E.164.
How do I change phone number format in Excel?: For display only, select the cells and use Format Cells > Special > Phone Number, which works for 10-digit US numbers stored as numbers. To change the stored value to E.164 for any country, export the column as CSV, format it here, and import the new column back.
Can I format phone numbers in a CSV without losing other columns?: Yes. Upload the CSV and the tool finds the phone column, formats it, and adds the formatted number, E.164, country, extension and status as new columns. Every original column stays in the download in its original order.
Does a valid format mean the phone number works?: No. It means the number fits an allocated range in its country's numbering plan. Whether the line is in service, who the carrier is and whether it is mobile or landline can only come from a live carrier lookup, which this free tool does not do.
Why did some numbers fail to format?: Usually one of three things: a digit is missing or extra, the default country is wrong for a number written without a + code, or the prefix isn't allocated, which is common with test and made-up numbers. Those rows are kept and labelled so you can fix them.
Is my list sent to a server?: No. Formatting runs in your browser with Google's open-source libphonenumber data, the same data Android uses. Nothing you paste or upload leaves your device.

Sources

Well formatted is not the same as reachable.

This tool fixes how numbers are written. It cannot tell you whether a line is mobile, landline or VoIP, or which carrier holds it. That takes a live carrier lookup, which is what the Email + Phone plan adds.

Upload a CSV up to 100,000 rows with an email or phone column
5,000 live carrier lookups a month: carrier name and real line type
Emails in the same file get a real SMTP mailbox check

Get started — $29.99/mo See the published limits first

One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.