How to clean a phone number list
Paste entries into Phone numbers or upload a TXT, CSV, or TSV file. The cleaner separates the entries, applies the selected country and extension rules, and places the results in Retained list, Duplicates removed, or Flagged - needs review.
- Paste entries into Phone numbers, or drop a TXT, CSV, or TSV file into Drop a TXT, CSV, or TSV file here and select browse files.
- Choose a Default country for entries without a leading
+. Select None - require + prefix when each entry must provide its own country signal. - Check Require explicit + prefix (flag everything else) to send entries without a leading
+to review. - Choose an Output format and an Extensions rule, then inspect Retained list, Duplicates removed, and Flagged - needs review.
- Use Copy, Export TXT, or Export CSV for retained entries. Duplicates removed and Flagged - needs review have separate Export CSV buttons.
How phone number list parsing works
Each non-empty piece separated by a newline, comma, semicolon, or tab becomes one entry. The cleaner trims surrounding spaces, keeps digits, and drops other punctuation while it reads the number. Only a leading + counts as an international prefix. A 00 prefix stays in the digits and is not converted to +.
The same separator rule applies to TXT, CSV, and TSV input. Quoted commas, tabs, or semicolons still act as separators, so quoted fields can produce extra entries.
How to normalize phone numbers and extensions
Set Default country for entries without +. The selected country supplies a calling code, trunk-prefix rule, national-number length range, and display grouping. For an entry with +, the cleaner matches a calling code from its country table. Require explicit + prefix (flag everything else) takes priority over Default country.
Extensions detects a trailing ext, ext., extension, x, or # followed by one to six digits. Choose Strip extension to leave it out, or Keep as ;ext=N to append it to the normalized number.
+1 (415) 555-2671
+44 20 7946 0958 ext 12With E.164 and Strip extension, the entries become:
+14155552671
+442079460958With Keep as ;ext=N, the second result ends in ;ext=12. National output uses the selected country's configured trunk prefix. Display output adds the calling code and groups the national digits.
How to remove duplicate phone numbers and review flags
After normalization, the first entry with a given country, national number, and extension is retained. Later entries with the same key appear in Duplicates removed with the original entry and the normalized value.
Flagged - needs review contains entries with no digits, letters outside a recognized extension marker, no country signal, an unrecognized or unassigned calling code, an unusual national-number length, or a missing + when explicit prefixes are required. The table shows the original text and reason.
Where phone number cleaning comes up
A support team can paste numbers collected in different regional formats, choose the relevant Default country, and export one E.164 list for a contact import. A sales analyst can keep extensions attached with Keep as ;ext=N.
A data steward can compare Duplicates removed before deciding which source rows to keep. Someone preparing a national calling list can choose National output and inspect flagged entries before sharing the export.
When to use another dataset cleaning tool
This page belongs to Dataset Clean Tools and handles phone-number structure. Choose Email List Cleaner for email casing, whitespace, duplicates, and malformed addresses. Choose Number & Currency Normalizer for numeric or currency values. Choose Data Cleaner for shared cleanup across CSV, TSV, Excel, JSON, JSONL, XML, or YAML input.
The cleaner splits, matches countries, normalizes, and formats in the browser. Its code reads the pasted value or local file and does not send the list through a fetch, XMLHttpRequest, sendBeacon, or form post.
Frequently Asked Questions
How do I clean a phone number list?
Paste the list into Phone numbers or upload a TXT, CSV, or TSV file. Choose the country and output rules, then review Retained list, Duplicates removed, and Flagged - needs review.
How do I normalize phone numbers without a country prefix?
Select a Default country to apply its calling code and trunk-prefix rule. If None - require + prefix is selected, an entry without + is flagged because the cleaner cannot determine its country.
How can I keep phone number extensions?
Choose Keep as ;ext=N under Extensions. A trailing ext, ext., extension, x, or # followed by one to six digits is added to the normalized output.
Does this phone number cleaner verify live numbers?
The length ranges identify entries for review. The cleaner does not check carrier assignment or confirm that a number is live or reachable.