Bulk Format Phone Numbers in CSV to E.164 Standard

Are messy phone formats like 06.12.34.56.78, +33(0)6..., or missing country codes ruining your cold calling and SMS campaigns?

CleanMyCSV normalizes phone numbers into clean international E.164 formats automatically.

E.164 International Standard
Twilio & Dialer Ready
Anti-ID Protection Guard

How CleanMyCSV Fixes Phone Number Messes

Sales prospects and scraped lead lists come with erratic phone number formatting. Here is how our normalization engine cleans your file:

1. E.164 International Country Code Addition

Auto-dialers (Salesloft, Outreach, RingCentral) and SMS tools (Twilio, Klaviyo) require phone numbers starting with international prefix codes. CleanMyCSV converts local numbers into standard E.164 formats (e.g., turning 06 12 34 56 78 into +33 6 12 34 56 78 for EU or 5550192834 into +1 (555) 019-2834 for US).

2. Parasitic Symbol & Extension Extraction

Lead databases often combine multiple phone numbers (0612345678 / 0123456789) or append office extension tags (ext. 102). Our engine isolates primary phone numbers, extracts extension suffixes cleanly, and strips parasitic characters (dots, slashes, brackets).

3. Recovery of Initial Zeros Dropped by Excel

Opening a CSV in Excel frequently strips the leading zero from local numbers, turning 0612345678 into a 9-digit string 612345678. CleanMyCSV detects truncated phone columns and restores missing leading zeros before formatting.

4. Anti-ID Safeguard for Technical Codes

Unlike naive regex tools that alter every long number string, CleanMyCSV features a smart Anti-ID safeguard. Numeric strings exceeding 13 digits without standard phone punctuation (such as SIRET business numbers, EAN barcodes, or transaction IDs) are protected and left untouched.

Ensure 100% dialer connectivity for your sales outreach lists.

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Pro Annual Pass

$99

  • Unlimited cleans for 1 year
  • Files up to 100MB (~1 million rows)
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$9

  • Unlimited cleans for 24 hours
  • Files up to 100MB (~1 million rows)
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Free Trial

$0

  • 2 free cleans per day
  • Files up to 5MB (~50,000 rows)