Format phone numbers in a CSV
Contact exports mix (415) 555-0132, 415.555.0198 and +44 20 7946 0958 in the same column, which trips up SMS tools, dialers and CRM matching. Upload the file and SpreadsheetFix rewrites each number in E.164 form (a plus sign, the country code and the digits, nothing else) and flags cells that can’t be a phone number. It all runs in your browser. Normalize Phone and Validate Phone are Pro rules.
- Plan
- Pro rule
- Account
- Not required
- Upload
- None
No file to hand?
Before and after
name,phone Ana Ruiz,(415) 555-0132 Ben Ode,415.555.0198 Cara Lin,+44 20 7946 0958 Dev Rao,0044 161 496 0753 Eli Park,ask reception
name,phone Ana Ruiz,+14155550132 Ben Ode,+14155550198 Cara Lin,+442079460958 Dev Rao,+441614960753 Eli Park,ask reception
1 row flagged for review: “ask reception” isn’t a phone number. It stays in the file and is listed in a separate quarantine download.
How it works
- 1
Upload your contact list as CSV or Excel. With Pro, Normalize Phone and Validate Phone are switched on for you.
- 2
Open the column picker on Normalize Phone and tick only your phone columns, so order numbers, dates and other long digit strings are left alone.
- 3
Run the rules, check the rewritten numbers and flagged rows in the preview, then download.
What E.164 looks like
E.164 is the international standard for writing phone numbers: a +, the country code, then the national number with no spaces, dashes or brackets. It’s +14155550132 rather than (415) 555-0132. Twilio, most SMS and calling platforms and many CRMs expect it, and because each number has exactly one spelling, duplicate contacts become easy to spot. SpreadsheetFix removes every character except digits and a leading +, turns a 00 international prefix into +, and leaves numbers that already start with + otherwise as they are.
Numbers without a country code are treated as US or Canadian
A number like 415.555.0198 doesn’t say which country it belongs to, so SpreadsheetFix assumes +1, the North American code, and drops any leading zeros before adding it. That is right for US and Canadian lists but wrong for local numbers from elsewhere: a UK number written 020 7946 0958 would become +12079460958. If your file has numbers from other countries, make sure they include their country code (+44… or 0044…) before cleaning. Those convert correctly.
Pick the phone column first
Normalize Phone rewrites any cell with seven or more digits in the columns it is given. Left on all columns, it would also turn an order number like 1002345 into +11002345, or a date like 2024-03-04 into +120240304. Open the column picker on the rule and select only your phone columns. Validate Phone already limits itself to columns whose header contains phone, tel, mobile, cell or fax.
What gets flagged
After formatting, Validate Phone checks each phone cell: an optional + followed by 7 to 20 characters made only of digits, spaces, dashes, dots and brackets. Cells containing words, like “ask reception” or “n/a”, fail, and the row is flagged. Flagged rows stay in the cleaned file and are also listed in a quarantine file you can download, so you can fix them by hand.
Questions
How do I format phone numbers in a CSV file?
Upload the file above, limit Normalize Phone to your phone column with the column picker, and run it. Every number becomes a + and country code followed by digits, and you download the cleaned CSV. Both phone rules are part of Pro.
What happens to phone extensions?
Extensions aren’t recognised. Their digits are appended to the number, so 415-555-0101 ext. 12 becomes +1415555010112. Move extensions into their own column before cleaning.
Can I format numbers for a country other than the US?
Numbers that already include a country code, written as +44 or 0044, are converted correctly for any country. Numbers without one are assumed to be +1 (US and Canada), and there’s currently no setting to change that default.
Does it check that a number is real?
No. It checks that the cell looks like a phone number, not that the number exists or has the right length for its country. Nothing is looked up online, so your contacts never leave your browser.
Is phone formatting free?
No. Normalize Phone and Validate Phone are Pro rules (€12/month). On the free plan you can still upload a file, and the health report counts the invalid phone numbers it finds.