Bulk Phone to E.164 Converter

How to use the E164 converter

This E164 converter rewrites a whole column of phone numbers in E.164, the format ad platforms such as Google's Customer Match use to match customers by phone. It adds the missing country code, checks that each number can exist, and tells you whether it is a mobile, a landline or a toll-free line.

1. Add the numbers. Load a CSV or Excel file, or paste one number per line. Other columns in your file stay as they are.
2. Check the phone column. The tool finds headers like Phone, Mobile or Billing Phone. If your file has a country column, map it too.
3. Choose the default country. It decides how a number like 0491 570 156 is read when it has no + and the row has no country.
4. Review the flags. It works as an E.164 format checker too: every row gets a status — Valid, Check, Invalid or Empty — plus the number type, the detected country, its country code and how that code was found.
5. Download. Get the full file with the new columns, or a clean one-column list of valid numbers without duplicates.

What this E.164 phone number converter cleans up

• Spaces, dots, dashes and brackets: 415.555.0187 → +14155550187.
• Trunk zeros: the 0 at the start of UK, German, French or Australian numbers.
• 00 international prefixes and (0) written after the country code.
• Extensions, which are not part of E.164, and prefixes such as p: or tel:.
• Spreadsheet damage: scientific notation like 1.4155E+10, a trailing .0, or a lost leading zero.
• Two numbers in one cell: the first is converted, and the row is flagged. Vanity numbers like 1-800-FLOWERS and numbers Excel cut short are flagged with the fix.

What to do with your E.164 numbers

1. Building an audience? Hand the list to the formatter for Google Customer Match, Meta or TikTok. Each one adds its own column names and hashing rules on top of E.164.
2. Fixing your CRM? Import the E.164 column back into the phone field, and set that field (or spreadsheet column) to Text so the + and every digit survive the next export.
3. Sending SMS or WhatsApp? Many messaging tools also want E.164. Remove the rows marked Invalid first, and look at the Check rows by hand.
4. Hashing for an API? Hash the column in the form that platform asks for: the + version for Google, the digits-only version for Meta.

Common phone number problems

E.164 format for UK, Australia and India numbers

These countries write numbers with a leading 0 at home: 07400 123456, 0491 570 156, 098765 43210. In E.164 that 0 goes away: +447400123456, +61491570156, +919876543210. Keeping the 0 after the country code is one of the most common mistakes.

The leading zero or the + sign disappeared in Excel

When a column is formatted as a number, Excel removes leading zeros and the plus sign, and long numbers turn into 1.4155E+10. The converter rebuilds what it can and flags those rows. Next time, format the column as Text before you paste.

Numbers read with the wrong country

Without a + or a country column, the default country decides. A list of Canadian customers converted with "United Kingdom" as default gives wrong or invalid results. Mixed lists need a country column.

Numbers marked "Check"

They have the right length but use an area code or range that isn't assigned. Some are typos, some are fake numbers typed into forms. Ad platforms can't match them, so fix or remove them.

Toll-free and company numbers

A 1-800 or other toll-free number is valid, but it belongs to a business, not a person. It is flagged as a note, because it rarely matches anyone in an ad platform.